Fasting Nonesterified Fatty Acids Research Articles

Role of Adiponectin in the Androgen-Mediated Cardiometabolic Complications in a Rat Model of Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in reproductive-age women and is associated with a high prevalence of obesity, adipose insulin resistance (adipose IR), and insulin resistance (IR). Adipose IR is an early metabolic defect in the development of whole-body IR. Specific evaluation of adipose IR and its consequences on the whole-body metabolic state in women with PCOS has not been thoroughly investigated. Adiponectin is a peptide secreted by adipocytes that increases insulin sensitivity. PEG-BHD1028 is a novel potent peptide adiponectin receptor agonist. Despite that PEG-BHD1028 modulates insulin sensitivity in different models of diabetes, the potential of PEG-BHD1028 to attenuate androgen-mediated adipose IR and obesity remains unknown. Hypothesis: We tested the hypothesis that PEG-BHD1028 attenuates adipose IR and obesity in a rat model of PCOS. Methods: To induce PCOS, four-week-old female Sprague Dawley rats were implanted with dihydrotestosterone (DHT) silastic tubes (7.5 mg) or placebo (PBO) for 90 days (n=4-8/group). During the final three weeks of DHT treatment, rats received PEG-BHD1028 (25 μg/kg/day) subcutaneously. Body weight (BW) by gravimetry, fat and lean mass were measured by Echo-MRI. Fasting plasma insulin was measured by ELISA. Fasting plasma glucose and non-esterified fatty acids (NEFA) were measured with a clinical chemistry analyzer. HOMA-IR, an index of systemic IR, and adipose IR (fasting insulin x fasting NEFA) were calculated. Protein levels of insulin signaling markers including IRS1, p-IRS1 (Ser1101), PI3 kinase p110, Akt, p-Akt (SER473), GLUT4, mTOR, p-mTOR (Ser2481) were quantified in the retroperitoneal fat by Western-blot. Results: DHT significantly (p<0.05) increased BW (352.67± 6.93 vs 250.88 ± 5.26 g), fat mass (20.82 ± 1.48 vs 9.44 ± 1.81 g), and lean mass (316.92 ± 4.15 vs 224.45 ± 4.79 g), compared to PBO group. DHT significantly (p<0.05) increased HOMA-IR and adipose IR by 75% and 80%, respectively, compared to PBO group. DHT downregulated retroperitoneal fat p-IRS-1, IRS-1, p-mTOR, mTOR, GLUT4, PI3 kinase and Akt protein expression by 50% to 70% while upregulating p-Akt by 1.8- fold compared to the PBO group. PEG-BHD1028 significantly decreased BW, fat mass and lean mass while attenuating IR by 34.7% reduction in HOMA-IR and significantly (p<0.05) decreased adipose IR by 51.6% in PCOS rats. Interestingly, PEG-BHD1028 significantly (p<0.05) upregulated p-IRS-1, IRS-1, p-mTOR, mTOR and p-AKT levels by 2.6-, 3-, 2.2-, 4-, 2.6- fold, respectively with no impact on the other insulin signaling markers compared to vehicle-treated group. Conclusion: PCOS rats exhibit obesity and lower adiponectin levels that are associated with both adipose and whole-body insulin resistance. Activating adiponectin receptors with PEG-BHD1028 attenuated PCOS-associated obesity and adipose IR. Significance: Targeting adiponectin signaling could be a novel and effective therapeutic approach to mitigate metabolic dysfunction in females with excess androgens. Supported by NIH-NIGMS grant P20GM121334 (L.L.Y.C. and D.G.R.), NIH-NIGMS grant P20GM121334, P20GM104357, NIH-NHLBI grant P01HL51971, NIH-NIMHD-P50MD017338 and University of Mississippi Medical Center Medical Student Research Program (R.C.) and the Robert M. Hearin Foundation (R.C.). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract P175: Total Fasting and Post-Load and Individual Fasting Non-Esterified Fatty Acids and Total and Cause-Specific Mortality: The Cardiovascular Health Study

Background: Total fasting non-esterified fatty acid (NEFA) levels have been associated with total and cause-specific mortality in older adults, but the corresponding associations with NEFA levels following the metabolic challenge of an oral glucose tolerance test (OGTT) and with individual fasting NEFA species have not been quantified Methods: We studied 1996 participants from the Cardiovascular Health Study with a mean age of 78 years who had total serum NEFA measured enzymatically before and two hours after an OGTT and fasting individual NEFA measured using gas chromatography in samples collected in 1996-1997. 1678 participants died over a median follow-up of 11 years. Multivariable Cox proportional hazard models were used to evaluate adjusted hazard ratios (aHR) for mortality associated with standard deviation increments of fasting and post-load total NEFA and fasting individual and subclasses (saturated, monounsaturated, n-3 and n-6 polyunsaturated, and trans) Results: Fasting NEFA were associated with an increased risk of all-cause mortality (aHR 1.17, 95% CI 1.10 - 1.23). In contrast, levels of post-load NEFA were not associated with mortality (aHR 0.98, 95% CI 0.93 - 1.03). Among NEFA subclasses, only monounsaturated fatty acid (MUFA) were associated with total mortality (aHR 1.24, 95% CI 1.09 - 1.41). In cause-specific analyses, MUFA were associated with higher risk of death from dementia, cardiovascular, respiratory, infectious and kidney disease. For individual NEFAs, nervonic acid (aHR 1.06, 95% CI 1.01 - 1.12) and petroselaidic acid (aHR 1.21, 95% CI 1.03 - 1.42) were associated with higher risk of all-cause mortality whereas eicosapentaenoic acid (aHR 0.90, 95% CI 0.82 - 0.99) was associated with lower risk Conclusion: Among community-dwelling older adults, total fasting but not post-load NEFA were associated with higher risk of death. Among subclasses and individual species, MUFA, nervonic, and petroselaidic acids were associated with higher risk, and eicosapentanoic acid with lower risk, of mortality.

NEFA Dynamics in Adults With Severe Obesity and Insulin Resistance: No Coupling to the rs9939609 FTO Risk Allele.

The FTO gene is highly expressed in adipose tissues; however, whether nonesterified fatty acids (NEFA) dynamics are impacted by FTO has not been rigorously tested for in a uniformly obese study population comprising both sexes. To test for associations of the rs9939609 FTO risk allele with NEFA suppression. We investigated 97 subjects with severe obesity but without diabetes, having genotype TT (n = 32), AT (n = 31), or AA (n = 34) in a cross-sectional observation study. NEFA suppression was assessed from a low-dose hyperinsulinemic euglycemic clamp with glucose-tracer as well as from the response to a standardized meal. Insulin sensitivity was assessed by hepatic and total insulin sensitivity measurements in the clamp and by the Matsuda index during the meal. Variables of possible importance for NEFA dynamics were primarily assessed by linear regression. No genotype associations with fasting or suppressed NEFA were found, whether in the clamp or meal situation (P > .7 for all comparisons). Independent of genotype, higher fasting concentrations of NEFA and larger NEFA suppression were found in female compared with male subjects. Fasting NEFA or degree of suppression were not associated with total fat mass or body mass index. The respiratory quotient was negatively associated with NEFA suppression. In a gender-mixed adult population of obese individuals, an FTO obesity-risk allele did not affect fasting NEFA nor suppression thereof. These negative results on NEFA dynamics appear strengthened by the documentation of gender influence and associations with parameters reflective of insulin resistance.

Abstract P308: The Determinants of Fasting and Post-Load Non-Esterified Fatty Acids in Older Adults: The Cardiovascular Health Study

Aim: Non-esterified fatty acids (NEFA) are associated with key cardiometabolic diseases of aging and are potential targets for prevention, but their population-level correlates remain uncertain. We sought to identify modifiable factors associated with higher fasting and post-load NEFA levels in older adults. Methods: We used linear multivariable regression models to determine the cross-sectional associations of demographic, anthropometric, lifestyle characteristics, and medication use with serum fasting and post-load NEFA concentrations amongst community-dwelling older adults enrolled in the Cardiovascular Health Study (n = 1,924). Results: In general, fasting NEFA levels demonstrated a broader set of determinants, while post-load NEFA were more consistently associated with metabolic factors. Waist circumference and weight were associated with higher fasting and post-load NEFA. Cigarette smoking and caffeine intake were associated with lower levels of both species, and moderate alcohol intake was associated with higher fasting levels whereas greater consumption was associated with lower post-load levels. Unique factors associated with higher fasting NEFA included female sex, higher age, loop and thiazide diuretic use and calcium intake, while factors associated with lower fasting levels included higher educational attainment, beta-blocker use, and protein intake. Hours spent sleeping during the daytime were associated with higher post-load NEFA, while DASH score were associated with lower levels. Conclusion: Fasting and post-load NEFA appear to have both common and unique modifiable risk factors, including sociodemographics, anthropometric, medications, and diet. Post-load NEFA were particularly sensitive to metabolic factors, while a broader range of determinants were associated with fasting levels. These factors warrant further study as targets for lowering levels of NEFA in older adults..

Effects of a genetic variant rs13266634 in the zinc transporter 8 gene (SLC30A8) on insulin and lipid levels before and after a high-fat mixed macronutrient tolerance test in U.S. adults

BackgroundThe common C-allele of rs13266634 (c.973C>T or p.Arg325Trp) in SLC30A8 (ZNT8) is associated with increased risk of type 2 diabetes. While previous studies have examined the correlation of the variant with insulin and glucose metabolism, the effects of this variant on insulin and lipid responses after a lipid challenge in humans remain elusive. The goal of this study was to determine whether the C-allele had an impact on an individual’s risk to metabolic syndromes in U.S. adults. MethodWe studied the genotypes of rs13266634 in 349 individuals aged between 18 and 65 y with BMI ranging from 18.5 to 45 kg/m2. The subjects were evaluated for insulin, glucose, HbA1c, ghrelin, and lipid profiles before and after a high-fat mixed macronutrient tolerance test (MMTT). ResultsWe found that the effects of variants rs13266634 on glucose and lipid metabolism were sex-dimorphic, greater impact on males than on females. Insulin incremental area under the curve (AUC) after MMTT was significantly decreased in men with the CC genotype (p < 0.05). Men with the CC genotype also had the lowest fasting non-esterified fatty acid (NEFA) concentrations. On the other hand, the TT genotype was associated with a slower triglyceride removal from the circulation in men after MMTT. The reduced triglyceride removal was also observed in subjects with BMI ≥ 30 carrying either the heterozygous or homozygous T-allele. Nevertheless, the SNP had little effect on fasting or postprandial blood glucose and cholesterol concentrations. ConclusionWe conclude that the CC genotype negatively affects insulin response after MMTT while the T-allele may negatively influence lipolysis during fasting and postprandial blood triglyceride removal in men and obese subjects, a novel finding in this study.

Dysregulated carbohydrate and lipid metabolism and risk of atrial fibrillation in advanced old age

ObjectiveObesity and dysmetabolism are major risk factors for atrial fibrillation (AF). Fasting and postload levels of glucose and non-esterified fatty acids (NEFAs) reflect different facets of metabolic regulation. We sought...

Fasting and Post-Load Glucose and Non-Esterified Fatty Acids and Risk of Heart Failure and Its Subtypes in OlderAdults.

Glucose and non-esterified fatty acids (NEFA) are myocardial fuels whose fasting and post-prandial levels are under different homeostatic regulation. The relationships of fasting and post-load glucose and NEFA with incident heart failure (HF) remain incompletely defined. Serum glucose and NEFA were measured during fasting and 2 hours post-oral glucose tolerance test, performed in Cardiovascular Health Study participants not receiving hypoglycemic medication. Participants with prevalent HF or lacking relevant data were excluded. Outcomes were incident HF (primary), and HF with preserved (HFpEF) and reduced (HFrEF) ejection fraction (secondary). Among 2238 participants (age 78±4) with a median follow-up of 9.9years, there were 737 HF events. After adjustment for demographic and lifestyle factors, both fasting (hazard ratio [HR]=1.11 per SD [95% confidence interval {CI}=1.01-1.23], p=.040) and post-load (HR=1.14 per SD [1.05-1.24], p=0.002) glucose were significantly associated with incident HF. No association was seen for fasting or post-load NEFA. Upon mutual adjustment, only post-load glucose (HR=1.11 [1.003-1.22], p=.044), but not fasting glucose (HR=1.06 [0.94-1.20], p=.340), remained associated with HF. Further adjustment for cardiovascular disease and other risk factors in the causal pathway did not affect the association for post-load glucose, but eliminated that for fasting glucose. Associations for fasting and post-load glucose appeared stronger with higher adiposity and were observed specifically for HFrEF but not HFpEF. Fasting and post-load glucose, but not NEFA, were associated with incident HF. The association was especially robust for post-load glucose, suggesting that pathways involved in post-prandial dysglycemia could offer new targets for HF prevention late in life.

Postprandial Responses of Energy Substrates in Dogs Fed High Fat‐ vs High Protein‐Low Carbohydrate Ketogenic Foods Relative to a High Carbohydrate Food

ObjectiveReduction of dietary carbohydrate (CHO) can increase circulating ketone availability and may aid disease management including inflammatory bowel disease, cancer, diabetes and cognitive decline. Companion animal dogs are prone to all of these maladies. Postprandial to a mixed macronutrient meal, non‐esterified fatty acids (NEFA) and beta‐hydroxybutyrate (BHB) decrease. In contrast, both glucose and blood urea nitrogen (BUN) increase. Triglycerides (TG) comprise circulating fat energy after a fat‐containing meal although medium chain TG (MCT) are preferentially catabolized to ketones. The postprandial responses of dogs to habitual feeding of high fat versus high protein low CHO foods, relative to high CHO foods, is not known. Therefore, we compared fasting (0 hr) and 2‐0 hr delta values for BHB, NEFA, TG, glucose, BUN as markers of available energy for these foods in dogs.MethodsDogs housed in pairs, with daily group exercise in outdoor grassy runs. Dogs returned to the colony healthy after the study; no invasive procedures. Blood collections under approved protocols at 0 hours (immediately before a meal) and at 2 hours postprandial. Macronutrients (P/F/C; % energy) for the 3 foods: HiCHO (25/37/38); LoCHOprot (50/44/6); LoCHOfat (28/68/4). The LoCHOfat food further contained 22% of dietary fat energy as MCT. Prospective randomized crossover trial (2 groups, n = 18). HiCHO was the wash‐in food followed by LoCHOprot or LoCHOfat in randomized order (5 wk feeding each food). Foods analyzed according to AOAC methods. Energy substrates BHB, NEFA, TG, glucose and BUN measured by Cobas or enzymatic reaction. Individual diet differences by dependent samples t‐test, linear mixed modeling for overall diet effect. Significance at α = 0.05.ResultsAnalyzed ketogenic ratios of the foods: HiCHO (0.46), LoCHOprot (1.1), and LoCHOfat (1.7). At fasting, LoCHOprot and LoCHOfat elevated circulating BHB above HiCHO food with LoCHOfat BHB higher than LoCHOprot. Between 0‐2 hours postprandial, BHB decreased for HiCHO (‐23%) and increased more for LoCHOfat (+100%) than LoCHOprot (+33%). Fasting NEFA were higher in LoCHOprot than LoCHOfat, and not different otherwise. From 0‐2 hours postprandial all foods showed decreased NEFA: HiCHO (‐43%), LoCHOprot (‐57%), LoCHOfat (‐12%). Fasting glucose was not different between groups. From 0‐2 hours postprandial LoCHOprot (‐4%) and LoCHOfat (‐8%) showed decreased glucose while HiCHO was unchanged. Fasting TG levels were different between all foods with the LoCHOprot (‐45%) and LoCHOfat (‐37%) lower than HiCHO. From 0‐2 hours postprandial all dogs showed increased TG with all values different between groups: HiCHO (+135%), LoCHOprot (+356%), LoCHOfat (+591%). Fasting BUN was higher with LoCHOprot than either HiCHO (‐27%) or LoCHOfat (‐26%). From 0‐2 hours postprandial all dogs showed increased BUN with all changes different: HiCHO (+17%), LoCHOprot (+42%), LoCHOfat (+23%).ConclusionsThe LoCHOfat food increased postprandial availability of BHB, NEFA and TG energy while decreasing glucose energy. LoCHOprot primarily enhanced available energy from protein as shown by increased amino acid catabolism to BUN, with additional contributions from BHB, NEFA and TG. The HiCHO food presented only glucose and TG as energy postprandial. Together these data show that a moderate protein, high fat, low CHO food with added MCT can selectively apportion postprandial energy toward ketone and fats while decreasing availability of glucose.

Fasting and Postload Nonesterified Fatty Acids and Glucose Dysregulation in Older Adults.

To evaluate the association of nonesterified fatty acids (NEFA) with dysglycemia in older adults, NEFA levels were measured among participants in the Cardiovascular Health Study (United States; enrolled 1989-1993). Associations with insulin sensitivity and pancreatic β-cell function, and with incident type 2 diabetes mellitus (DM), were examined. The sample comprised 2,144 participants (aged 77.9 (standard deviation, 4.5) years). Participant data from the Cardiovascular Health Study visit in 1996-1997 was used with prospective follow-up through 2010. Fasting and postload NEFA showed significant associations with lower insulin sensitivity and pancreatic β-cell function, individually and on concurrent adjustment. Over median follow-up of 9.7 years, 236 cases of DM occurred. Postload NEFA were associated with risk of DM (per standard deviation, hazard ratio= 1.18, 95% confidence interval: 1.08, 1.29), but fasting NEFA were not (hazard ratio= 1.12, 95% confidence interval: 0.97, 1.29). The association for postload NEFA persisted after adjustment for putative intermediates, and after adjustment for fasting NEFA. Sex and body mass index modified these associations, which were stronger for fasting NEFA with DM in men but were accentuated for postload NEFA in women and among leaner individuals. Fasting and postload NEFA were related to lower insulin sensitivity and pancreatic β-cell function, but only postload NEFA were associated with increased DM. Additional study into NEFA metabolism could uncover novel potential targets for diabetes prevention in elders.

Abstract 12796: Fasting and Post-Load Glucose and Non-Esterified Fatty Acids and Risk of Heart Failure and Its Subtypes in Older Adults

Introduction: Glucose and non-esterified fatty acids (NEFA) are myocardial fuels whose fasting and postprandial levels are under different homeostatic regulation. The relationships of fasting and postload glucose and NEFA with incident HF and its subtypes remain incompletely defined. Methods: We hypothesized that fasting and postload glucose and NEFA are positively associated with incident HF in older adults, with postload levels bearing stronger associations. Serum glucose and NEFA levels were measured during fasting and 2 hours post oral glucose tolerance test in the Cardiovascular Health Study. HF with preserved (HFpEF) and reduced ejection fraction (HFrEF) were examined secondarily. Results: Among 2238 people (age 78±4) with median follow-up of 9.9 years, there were 737 HF events (257 classifiable as HFpEF, 197 as HFrEF). After adjustment for demographic and lifestyle factors (main model), both fasting (HR per SD 1.11 [95% CI 1.01-1.23]) and postload (HR per SD 1.14 [1.05-1.24]) glucose was significantly associated with incident HF. No association was seen for fasting or postload NEFA. When adjusted for each other, only postload glucose (HR 1.11 [1.003-1.22]), but not fasting glucose (HR 1.06 [0.94-1.20]), remained associated with HF. Further adjustment for prevalent atherosclerotic cardiovascular disease, atrial fibrillation and other risk factors in the causal pathway did not affect the association for postload glucose, but eliminated that for fasting glucose. There was no interaction by sex, but associations for fasting and postload glucose appeared stronger with higher BMI (p&lt;0.025). Assessment of HF subtypes showed no associations for glucose or NEFA with HFpEF. Both fasting glucose (HR 1.23 [1.03-1.48]) and postload glucose (HR 1.24 [1.07-1.45]) were significantly associated with HFrEF, but relationships disappeared on mutual adjustment. Conclusions: Fasting and postload glucose, but not NEFA, were associated with incident HF, particularly HFrEF. The association proved especially robust for postload glucose, which reflects pancreatic β-cell insufficiency and skeletal muscle decline. Our findings suggest that targeting relevant pathways in these two organ-tissues could offer new approaches for HF prevention in elders.

Abstract 14355: Metabolic Dysregulation and Incident Atrial Fibrillation in Older Adults

Introduction: Obesity and dysmetabolism are major risk factors for atrial fibrillation (AF). Fasting and post-load levels of glucose and non-esterified fatty acids (NEFA) reflect different facets of metabolic regulation, but their contributions to AF risk have not been studied simultaneously in prior studies. We assessed fasting and post-load glucose and NEFA in an older cohort to identify their independent associations with new-onset AF, and secondarily with baseline ECG parameters known to be markers of AF risk. Methods: This study focused on participants from the community-based Cardiovascular Health Study who were free of prevalent AF and had serum collected in the fasting state and after an oral glucose tolerance test. Maximal p wave duration and p wave terminal force in V1 (PTFV1) were measured from 12-lead ECG. Associations were evaluated with linear regression for ECG parameters, and Cox regression for AF. Results: The study included 1,877 participants (age 77.7±4.4). After adjustment, both fasting and post-load glucose, but not NEFA, were positively associated with higher PTFV1. When fasting and post-load glucose were entered together, only the relationship for the latter remained significant (63 μV*ms greater PTFV1 per SD increment in post-load glucose [p=0.028]). During median follow-up of 11.4 years, 717 cases of incident AF occurred. Post-load glucose, but not fasting glucose or either NEFA measure, showed an association with incident AF (adj. HR per SD=1.11 [95% CI=1.02, 1.21], p=0.017). There was significant interaction by sex (p=0.015). The positive relationship of post-load glucose with AF was observed in women (adj. HR per SD=1.21 [1.09, 1.35], p&lt;0.001), but not men (adj. HR per SD=0.97 [0.85, 1.12], p=0.714). Conclusions: Among older adults, post-load glucose, but not fasting glucose or NEFA measures, was positively associated with incident AF, with consistent findings for PTFV1 on baseline ECG. The relationship with AF appeared specific to women. Because post-load glucose is a marker of both pancreatic β-cell insufficiency and skeletal muscle decline, these findings suggest that interventions to address such tissue-organ dysfunction in older women might prevent AF in this high-risk population.

Serum Fasting Non-esterified Fatty Acids and Carotid Artery Intima-Media Thickness in Older Adults: The Cardiovascular Health Study

ObjectivesCarotid artery intima-media thickness (CIMT) has been used as an early indicator of subclinical atherosclerosis. Multiple studies have identified significant associations between plasma total non-esterified fatty acid (NEFA) concentrations and risk factors associated with subclinical atherosclerosis. However, the relationship between CIMT and serum NEFA is less clear. We hypothesized fasting serum total, individual saturated, and trans NEFA are positively associated with, and individual monounsaturated, n-6 polyunsaturated (PUFA) and n-3 PUFA NEFA are inversely associated with, CIMT. MethodsWe investigated the associations between fasting serum NEFA, and CIMT assessed in 1998–1999 among Cardiovascular Health Study (CHS) participants (N = 1,569) not taking anti-diabetic medication. A total of 35 individual NEFAs were measured in stored specimens from 1996–1997 using gas chromatography. CIMT was determined using ultrasound images, and was defined as the sum of the maximum common CIMT at the far wall divided by its standard deviation (SD) and the maximum internal CIMT at the far wall divided by its SD. At baseline, mean age was 77.3 ± 4.2, body mass index (BMI) was 26.8 ± 4.3 and 64% were female. Associations were assessed by linear regression, with adjustments for other individual NEFAs, age, sex, race, field center, education, smoking, BMI, physical activity, alcohol consumption, eGFR, serum albumin, hyperglycemia, hypertension, use of anti-hypertensive, statin, and other lipid-lowering drugs. ResultsIn adjusted models per SD increment, linoelaidic acid (trans18:2) was positively associated with CIMT [β (95% confidence interval): 10.4 (0.99, 19.8), P = 0.03], and α-linolenic acid (18:3n-3) was marginally associated with lower CIMT [–21.2 (–42.6, 0.2), P = 0.05]. No significant associations were observed between total NEFAs or any other individual NEFAs (SFA, MUFA, and n-6 PUFA) and CIMT. ConclusionsIn this large community-based cohort of older adults, higher concentration of linoelaidic acid was positively associated with CIMT, suggesting the importance of partially hydrogenated fat in the development of subclinical atherosclerosis in older adults. Overall, however, serum fasting NEFAs were largely unrelated to subclinical atherosclerosis in CHS participants. Funding SourcesNIH, NHLBI, USDA.

Effects of a Self-Prepared Carbohydrate-Reduced High-Protein Diet on Cardiovascular Disease Risk Markers in Patients with Type 2 Diabetes.

We previously observed beneficial effects of a carbohydrate-reduced, high-protein (CRHP) diet on cardiovascular risk markers in patients with type 2 diabetes mellitus (T2DM) in a crossover 2 × 6-week trial, when all food was provided to subjects as ready-to-eat meals. Here, we report the results from a 6-month open label extension: 28 patients with T2DM were instructed to self-prepare the CRHP diet with dietetic guidance. At weeks 0, 6, 12, and 36, fasting and postprandial (4-h meal test) blood samples were collected for measurements of total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, triacylglycerol (TG), apolipoproteins A1 and B, non-esterified fatty acids (NEFA), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6. Diurnal blood pressure and heart rate were also assessed. At the end of the study (week 36), concentrations of fasting total and LDL-cholesterol, fasting and postprandial NEFA and TG, and fasting apolipoprotein-B, CRP and TNF-α concentrations were significantly lower compared with week 0 (p < 0.05). A significant decrease in diurnal heart rate was also observed. From week 12 to 36, an increase in HDL-cholesterol and apolipoprotein-A1 concentrations and a further reduction in fasting and postprandial NEFA (p < 0.05) were found. These changes were independent of minor fluctuations in body weight. We conclude that the substitution of dietary carbohydrate for protein and fat has beneficial effects on several cardiovascular risk markers in patients with T2DM, which are maintained or augmented over the next 6 months when patients select and prepare the CRHP diet on their own in a dietitian-supported setting.

Modest sleep restriction does not influence steps, physical activity intensity or glucose tolerance in obese adults.

Sleep restriction (SR) (<6h) and physical activity (PA) are risk factors for obesity, but little work has examined the inter-related influences of both risk factors. In a free-living environment, 13 overweight/obese adults were sleep restricted for five nights to 6h time-in-bed each night, with and without regular exercise (45min/65% VO2 max; counterbalanced design). Two days of recovery sleep followed SR. Subjects were measured during a mixed meal tolerance test (MMT), resting metabolic rate, cognitive testing and fat biopsy (n=8). SR increased peak glucose response (+7.3mg/dl, p=.04), elevated fasting non-esterified fatty acid (NEFA) concentrations (+0.1mmol/L, p=.001) and enhanced fat oxidation (p<.001) without modifying step counts or PA intensity. Inclusion of daily exercise increased step count (+4,700 steps/day, p<.001) and decreased the insulin response to a meal (p=.01) but did not prevent the increased peak glucose response or elevated NEFA levels. The weekend recovery period improved fasting glucose (p=.02), insulin (p=.02), NEFA concentrations (p=.001) and HOMA-IR (p<.01) despite reduced steps (p<.01) and increased sedentary time (p<.01). Abdominal adipose tissue (AT) samples, obtained after baseline, SR and exercise, did not differ in lipolytic capacity following SR. Fatty acid synthase protein content tended to increase following SR (p=.07), but not following exercise. In a free-living setting, SR adversely affected circulating NEFAs, fuel oxidation and peak glucose response but did not directly affect glucose tolerance or AT lipolysis. SR-associated metabolic impairments were not mitigated by exercise, yet recovery sleep completely rescued its adverse effects on glucose metabolism.

Serum Individual Nonesterified Fatty Acids and Risk of Heart Failure in Older Adults

Background: Heart failure (HF) is highly prevalent among older adults and is associated with high costs. Although serum total nonesterified fatty acids (NEFAs) have been positively associated with HF risk, the contribution of each individual NEFA to HF risk has not been examined. Objective: The aim of this study was to examine the association of individual fasting NEFAs with HF risk in older adults. Methods: In this prospective cohort study of older adults, we measured 35 individual NEFAs in 2,140 participants of the Cardiovascular Health Study using gas chromatography. HF was ascertained using review of medical records by an endpoint committee. Results: The mean age was 77.7 ± 4.4 years, and 38.8% were male. During a median follow-up of 9.7 (maximum 19.0) years, 655 new cases of HF occurred. In a multivariable Cox regression model controlling for demographic and anthropometric variables, field center, education, serum albumin, glomerular filtration rate, physical activity, alcohol consumption, smoking, hormone replacement therapy, unintentional weight loss, and all other measured NEFAs, we observed inverse associations (HR [95% CI] per standard deviation) of nonesterified pentadecanoic (15:0) (0.73 [0.57–0.94]), γ-linolenic acid (GLA) (0.87 [0.75–1.00]), and docosahexaenoic acid (DHA) (0.73 [0.61–0.88]) acids with HF, and positive associations of nonesterified stearic (18:0) (1.30 [1.04–1.63]) and nervonic (24:1n-9) (1.17 [1.06–1.29]) acids with HF. Conclusion: Our data are consistent with a higher risk of HF with nonesterified stearic and nervonic acids and a lower risk with nonesterified 15:0, GLA, and DHA in older adults. If confirmed in other studies, specific NEFAs may provide new targets for HF prevention.

Non‐Esterified Fatty Acids and Risks of Frailty, Disability, and Mobility Limitation in Older Adults: The Cardiovascular Health Study

Non-esterified fatty acids (NEFAs) play central roles in the relationship between adiposity and glucose metabolism, and they have been implicated in the pathogenesis of cardiovascular disease, but few studies have assessed their effects on complex geriatric syndromes like frailty that cross multiple organ systems. We sought to determine the relationships between NEFAs and incident frailty, disability, and mobility limitation in a population-based cohort of older persons. We analyzed 4,710 Cardiovascular Health Study (CHS) participants who underwent measurement of circulating total fasting NEFAs in 1992-1993 and were assessed for frailty in 1996-1997 and for disability and mobility limitation annually. We used ordinal logistic regression to model incident frailty, linear regression to model components of frailty, and Cox regression to model disability and mobility limitation in relation to baseline NEFAs. To ensure proportional hazards, we truncated follow-up at 9 years for disability and 6.5 years for mobility limitation. A total of 42 participants became frail and 510 became pre-frail over a 4-year period, and we documented 1,720 cases of disability and 1,225 cases of mobility limitation during follow-up. NEFAs were positively associated in a dose-dependent manner with higher risks of incident frailty, disability, and mobility limitation. The adjusted odds ratios for frailty were 1.37 (95% confidence interval [CI] = 1.01-1.86; P = .04) across extreme tertiles and 1.17 (95% CI = 1.03-1.33; P = .01) per standard deviation increment. The corresponding hazard ratios for incident disability were 1.14 (95% CI = 1.01-1.30; P = .04) and 1.11 (95% CI = 1.06-1.17; P < .0001); those for incident mobility limitation were 1.23 (95% CI = 1.06-1.43; P = .006) and 1.15 (95% CI = 1.08-1.22; P < .0001). Results were largely consistent among both men and women. Among individual components of frailty, NEFAs were significantly associated with self-reported exhaustion (β = .07; standard error = .03; P = .02). Circulating NEFAs are significantly associated with frailty, disability, and mobility limitation among older adults. These results highlight the broad spectrum of adverse health issues associated with NEFA in older adults.

Non-esterified fatty acids and telomere length in older adults: The Cardiovascular Health Study

BackgroundTelomeres shorten as organisms age, placing limits on cell proliferation and serving as a marker of biological aging. Non-esterified fatty acids (NEFAs) are a key mediator of age-related metabolic abnormalities. We aimed to determine if NEFAs are associated with telomere length in community-living older adults. Material and methodsWe cross-sectionally studied 1648 participants of the Cardiovascular Health Study (CHS) who underwent concomitant telomere length measurement from a sample of 4715 participants who underwent measurement of circulating total fasting NEFAs in stored specimens from their 1992-3 clinic visit. We used linear regression and inverse probability weighting to model telomere length as a function of NEFAs with adjustment for age, gender, race, clinic, BMI, marital status, smoking status, alcohol intake, diabetes status, years of education, hypertension status, prevalent cardiovascular disease, C-reactive protein, total adiponectin, albumin, fetuin-A, fasting insulin, eGFR, total cholesterol, HDL-cholesterol, triglycerides, and general health status. ResultsHigher NEFAs were significantly associated with shorter telomere length, after adjusting for age, gender, race, and clinic site (β = −0.034; SE = 0.015; P = 0.02). Estimates remained similar in fully adjusted models where each SD of NEFA increment was associated with 0.042 kilobase (kb) pairs shorter telomere length (standard error = 0.016; P = 0.007); for comparison the coefficient for a single year of age in the same model was −0.017. These results were similar in strata of sex, and waist circumference although they tended to be strongest among participants in the youngest tertile of age (β = -0.079; SE = 0.029; P = 0.01). ConclusionsIn this population-based cohort of community-living elders, we observed a significant inverse association between NEFAs and telomere length. If confirmed, NEFAs may represent a promising target for interventions to slow biological aging.

Age, Sex, and Depot-Specific Differences in Adipose-Tissue Estrogen Receptors in Individuals with Obesity.

The aim of this study was to examine the effects of sex and menopausal status on depot-specific estrogen signaling in white adipose tissue (AT) in age-matched men and women with morbid obesity. A total of 28 premenopausal women, 16 postmenopausal women, and 27 age-matched men undergoing bariatric surgery were compared for omental (OM) AT (OMAT) and abdominal subcutaneous (SQ) AT (SQAT) genes and proteins. With the exception of fasting nonesterified fatty acids being higher in women (P < 0.01), no differences were found in other indicators of glucose and lipid metabolism. In OMAT, estrogen receptor (ER) beta (ERβ) levels were higher in older women than in younger women and older men (sex-age interaction, P < 0.01), and aromatase expression was higher in older men than in older women (P < 0.05). In SQAT, women had lower expression of ERβ than men (P < 0.05). Protein content of ER alpha and ERβ was highly correlated with the mitochondrial protein uncoupling protein 1 across sexes and ages (P < 0.001). Age increased SQ inflammatory gene expression in both sexes. In morbid obesity, sex and age affect AT ERs, lipid metabolism, mitochondrial uncoupling protein 1, and inflammatory expression in an AT depot-dependent manner. The SQAT immunometabolic profile is heavily influenced by age and menopause status, more so than OMAT.

Sleep apnea in men is associated with altered lipid metabolism, glucose tolerance, insulin sensitivity, and body fat percentage

PurposeObstructive sleep apnea (OSA) is associated with obesity and risk for type 2 diabetes. In this community-based study, we thoroughly investigated fatty acid metabolism, incretin response, glucose tolerance, insulin secretion and insulin sensitivity, and autonomic nerve activity in men with or without OSA.MethodsFifteen men without diabetes but with signs of severe OSA, defined as apnea–hypopnea index (AHI) >30, and 15 age- and BMI-matched men without OSA (AHI < 5) were recruited from a community-based cohort. Assessments included clinical and anthropometric measurements, a 2-h oral glucose tolerance test (OGTT), and autonomic nerve activity using heart rate variability (HRV).ResultsMen with OSA had higher body fat % than BMI-matched men without OSA (p = 0.046) and it was associated with markers of insulin resistance. The area under the curve for nonesterified fatty acids (NEFA) during OGTT was higher in men with OSA (p = 0.021) and fasting NEFA levels were numerically higher (p = 0.097). The plasma glucose at fasting and during OGTT was higher in men with OSA (p < 0.001). Incretin response was similar between groups. Fasting and OGTT-derived indices indicated impaired insulin sensitivity in men with OSA. Compared with men without OSA, Matsuda index (p = 0.068) and Gutt index (p < 0.01) were lower in men with OSA. The HRV measures did not differ between groups.ConclusionsOur study suggests that fatty acid handling, glucose tolerance, and insulin sensitivity are impaired in men with severe OSA. This might partly be explained by the increased body fat percentage.

Abstract P560: Serum Non-esterified Fatty Acids and Risk of Incident Stroke in Older Adults: The Cardiovascular Health Study

Introduction: Serum non-esterified fatty acids (NEFAs) have been linked to both local and systemic inflammation and are higher in individuals with obesity, diabetes, cardiovascular disease, and ischemic stroke risk. Significant associations between total plasma NEFA concentrations and incident ischemic stroke have been reported in some but not all prospective studies. Given the functional and structural diversity among circulating NEFA, the associations of individual or clusters of circulating NEFAs may provide additional insight into their relationship with incident stroke. Hypothesis: Fasting serum n-3 NEFAs are inversely associated, and saturated and trans NEFAs are positively associated with incident stroke. Methods: We analyzed the incidence of stroke among Cardiovascular Health Study (CHS) participants who were free of stroke in 1996-1997 and underwent fasting NEFA profile measurement. At baseline, mean age was 77.8±4.5, body mass index was 26.7±4.4 and 61% were female. A total of 38 individual NEFAs in 5 classes (saturated, monounsaturated, polyunsaturated n-6, polyunsaturated n-3 and trans NEFAs) were measured using gas chromatography. Cox regression was used to evaluate the association of individual NEFA species with incident stroke, adjusting for: age, sex, race, and field center (model 1); model 1 covariates plus smoking, education, physical activity, alcohol consumption, eGFR, BMI, aspirin use, waist circumference, hypertension, prevalent diabetes, and cholesterol (model 2). Results: A total of 338 cases of incident stroke occurred during median follow-up of 10.5 years. In the fully adjusted model, trans -palmitoleic acid was inversely associated with incident stroke (HR per 1 mol% of NEFA composition: 0.03 [95% CI: 0.00 to 0.77], P &lt;0.03). Serum docosahexaenoic acid levels were associated with lower risk of incident stroke (HR: 0.63 [95% CI: 0.40 to 1.00], P &lt;0.05). Total n-3 fatty acids (HR: 0.78 [95% CI: 0.63 to 0.97]) and docosapentaenoic acid (HR: 0.12 [95% CI: 0.02 to 0.88]) were each associated with lower risk of incident stroke only in model 1. No significant association of saturated NEFAs with incidence of stroke was observed. Conclusion: Among fasting serum NEFA, docosahexaenoic acid and trans -palmitoleic acid were inversely associated with incident stroke, suggesting that these fatty acids may protect older adults from stroke.