Insulin Sensitivity In Women Research Articles

White blood cells levels and PCOS: direct and indirect relationship with obesity and insulin resistance, but not with hyperandogenemia.

To study white blood cells count (WBC) in women suffering from PCOS and compare these results with age and BMI-matched healthy women. The specific aim of this study was to assess the possible correlations of WBC with the major components of PCOS, obesity, insulin resistance and hyperandrogenism. Anthropometrical, metabolic and hormonal data were analyzed from 203 women with PCOS (NIH criteria) and 76 age-matched controls. In the total population studied (N=279), WBC was significantly higher (P=0.003) in the PCOS group compared with age-matched healthy women and was positively correlated with BMI (r=0.461, p<0.001), total testosterone (r= 0.210, p<0.001), insulin (r=0.271, p<0.001), triglycerides (r=0.285, p<0.001), HOMA score (r=0.206, p=0.001), FAI (r=0.329, p<0.001) and negatively correlated with SHBG (r=-0.300, p<0.001) and HDL (r=-0.222, p<0.001). Due to the fact that WHR was only available in the group of PCOS women, the role of central adiposity is assessed only in this group. Multiple regression analysis in the PCOS group, including WHR, revealed BMI, SHBG and TGL as the main predicting factors of WBC. Multinomial logistic regression analysis was also conducted and overweight/obesity was the sole independent risk factor for elevated WBC (higher tertile) (OR:0.907 CI:0.85-0.96, p=0.002). After dividing the sample based on BMI in the lean subgroups, WBC did not differ significantly between PCOS and controls, while multiple regression analysis indicated SHBG as the main predicting factor of WBC. Finally, we picked out the group of overweight/obese (BMI ≥25 kg/m2) women with PCOS and conducted another classification based on HOMA score (HOMA-IR≤2: insulin-sensitive women, HOMA-IR>2: insulin-resistant women) in the group of overweight and obese women with PCOS separately. In overweight women with PCOS, WBC, although higher in the group of insulin-resistant, did not differ significantly between the two groups, while in the subcategory of overweight women WBC was significantly (p=0.02) higher in the group of insulin-resistant women (HOMA-IR >2). Chronic low-grade inflammation and increased white cell count do occur in PCOS. Obesity and insulin resistance are the two leading parameters that act accumulatively in the development of leucocytosis, whereas hyperandrogenism does not seem to affect it.

Biomarkers and insulin sensitivity in women with Polycystic Ovary Syndrome: Characteristics and predictive capacity.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder associated with metabolic complications. Metabolic biomarkers with roles in obesity, glycaemic control and lipid metabolism are potentially relevant in PCOS. The aim was to investigate metabolic biomarkers in lean and overweight women with and without PCOS and to determine whether any biomarker was able to predict insulin resistance in PCOS. Cross-sectional study. Eighty-four women (22 overweight and 22 lean women with PCOS, 18 overweight and 22 lean women without PCOS) were recruited from the community and categorized based on PCOS and BMI status. Primary outcomes were metabolic biomarkers [ghrelin, resistin, visfatin, glucagon-like peptide-1 (GLP-1), leptin, plasminogen activator inhibitor -1 (PAI-1), glucose-dependent insulinotropic polypeptide (GIP) and C-Peptide] measured using the Bio-Plex Pro Diabetes assay and insulin sensitivity as assessed by glucose infusion rate on euglycaemic-hyperinsulinaemic clamp. The biomarkers C-peptide, leptin, ghrelin and visfatin were different between overweight and lean women, irrespective of PCOS status. The concentration of circulating biomarkers did not differ between women with PCOS diagnosed by the Rotterdam criteria or National Institute of Health criteria. PAI-1 was the only biomarker that significantly predicted insulin resistance in both control women (P = 0.04) and women with PCOS (P = 0.01). Biomarkers associated with metabolic diseases appear more strongly associated with obesity rather than PCOS status. PAI-1 may also be a novel independent biomarker and predictor of insulin resistance in women with and without PCOS.

Abstract P139: Insulin Resistance in Premenopausal Women with Type 1 Diabetes is Explained by Abdominal Obesity, Physical Inactivity and Altered Sex Hormones

Women with type 1 diabetes (T1D) lose the premenopausal protection from cardiovascular disease (CVD) that non-diabetic (non-DM) women have compared to men, and are also more insulin resistant than non-DM women. Standard CVD risk factors have not been found to adequately predict CVD in the T1D population, but insulin resistance is emerging as a potentially important risk factor. The aim of this study was to determine whether sex hormone levels such as estradiol (E2), total testosterone (TT), and sex-hormone binding globulin (SHBG) explained any of the decreased insulin sensitivity in women with T1D, which could be important in CVD prevention. This study included 25 premenopausal women 18-45 years of age with a mean ± SD age of 33 ± 8 years who completed a three stage (4, 8 and 40 mU/m2/min) hyperinsulinemic-euglycemic clamp during the luteal phase of the menstrual cycle (T1D n=12 and non-DM n=13). A steady state was achieved during the last 30 minutes of the high insulin infusion stage and mean glucose infusion rate (GIR [mg/kg/FFM/min]) during this time was used as an estimate of the skeletal muscle glucose disposal rate. Sex hormones were compared using unpaired Student t tests between T1D and non-DM participants during each phase of the menstrual cycle and during the morning of the clamp.. Significant differences were explored in multivariable linear regression in which stepwise model selection was used to determine the final model adjusting for age and diabetes status. In age-adjusted analysis, women with T1D were less than half as insulin sensitive as non-DM women (least squares mean ± SE: 7.5±2.2 vs. 19.0±2.1, respectively, p=0.0014). SHBG was significantly higher in the T1D than the non-DM subjects the morning of the clamp (p&lt;0.0001) and during each phase of the menstrual cycle (p = 0.01). TT was significantly higher in T1D women during the early follicular phase of the menstrual cycle (p=0.02) and was negatively correlated with GIR (r = -0.54, p = 0.04). E2 during the early follicular phase was positively correlated with GIR (r = 0.83, p = 0.01). In multivariable analysis, the difference in the GIR was attenuated by 58%(1-(5.1/12.14)) (least squares mean ± SE: 10.9 ± 1.7 in T1D vs. 16.0 ± 1.5 in non-DM, p = 0.07) after adjusting for age, diabetes status, minutes of vigorous activity, average waist circumference, free estradiol index and testosterone during the early follicular phase of the menstrual cycle In conclusion, the decreased insulin sensitivity observed in premenopausal T1D women with regular menstrual cycles can be mostly explained by lower levels of physical activity, greater central adiposity and differences in sex hormone levels. Most of these factors are modifiable, and so could be important targets in the reduction of CVD.

Metformin Improves Glucose Effectiveness, Not Insulin Sensitivity: Predicting Treatment Response in Women With Polycystic Ovary Syndrome in an Open-Label, Interventional Study

Although metformin is widely used to improve insulin resistance in women with polycystic ovary syndrome (PCOS), its mechanism of action is complex, with inconsistent effects on insulin sensitivity and variability in treatment response. The aim of the study was to delineate the effect of metformin on glucose and insulin parameters, determine additional treatment outcomes, and predict patients with PCOS who will respond to treatment. We conducted an open-label, interventional study at an academic medical center. Women with PCOS (n = 36) diagnosed by the National Institutes of Health criteria participated in the study. Subjects underwent fasting blood sampling, an IV glucose tolerance test, dual-energy x-ray absorptiometry scan, transvaginal ultrasound, and measurement of human chorionic gonadotropin-stimulated androgen levels before and after 12 weeks of treatment with metformin extended release 1500 mg/d. Interval visits were performed to monitor anthropometric measurements and menstrual cycle parameters. Changes in glucose and insulin parameters, androgen levels, anthropometric measurements, and ovulatory menstrual cycles were evaluated. Insulin sensitivity did not change despite weight loss. Glucose effectiveness (P = .002) and the acute insulin response to glucose (P = .002) increased, and basal glucose levels (P = .001) decreased after metformin treatment. T levels also decreased. Women with improved ovulatory function (61%) had lower baseline T levels and lower baseline and stimulated T and androstenedione levels after metformin treatment (all P < .05). Using an IV glucose tolerance test, which distinguishes improvements in glucose effectiveness and insulin sensitivity, metformin does not improve insulin sensitivity in women with PCOS but does improve glucose effectiveness. The improvement in glucose effectiveness may be partially mediated by decreased glucose levels. T levels also decreased with metformin treatment. Ovulation during metformin treatment was associated with lower baseline T levels and greater T and androstenedione decreases during treatment, but not with insulin or LH levels. Thus, the action of metformin in PCOS primarily affects glucose levels and steroidogenesis, which may be mediated by mechanisms that affect both pathways, such as inhibition of mitochondrial complex I.

Pronounced Reduction of Cutaneous Langerhans Cell Density in Recently Diagnosed Type 2 Diabetes

Immune-mediated processes have been implicated in the pathogenesis of diabetic polyneuropathy. Langerhans cells (LCs) are the sole dendritic cell type located in the healthy epidermis and exert tolerogenic immune functions. We aimed to determine whether alterations in cutaneous LC density and intraepidermal nerve fiber density (IENFD) are present in patients with recently diagnosed type 2 diabetes. Skin biopsy specimens from the distal leg from 96 type 2 diabetic patients and 75 healthy control subjects were used for quantification of LC density and IENFD. LCs and IENFs were labeled using immunohistochemistry. Nerve conduction studies, quantitative sensory testing, and neurological examination were used to assess peripheral nerve function. LC density was markedly reduced in the diabetic group compared with the control group, but did not correlate with reduced IENFD or peripheral nerve function. Multivariate linear regression analysis revealed a strong association between LC density and whole-body insulin sensitivity in women but not in men with diabetes. Prospective studies should establish whether the pronounced reduction of cutaneous LCs detected in recently diagnosed type 2 diabetes could promote a cutaneous immunogenic imbalance toward inflammation predisposing to polyneuropathy and foot ulcers.

Statin Therapy Worsens Insulin Sensitivity in Women With Polycystic Ovary Syndrome (PCOS): A Prospective, Randomized, Double-Blind, Placebo-Controlled Study

Statins have been shown to improve hyperandrogenism in women with polycystic ovary syndrome (PCOS). However, their use has also been associated with impairment of glucose metabolism and an increased risk of type 2 diabetes mellitus. Because women with PCOS are prone to disturbances in glucose metabolism, statin therapy could also have negative effects. Our objective was to explore the effects of atorvastatin therapy on hormonal and metabolic parameters in women with PCOS. We conducted a randomized, double-blind, placebo-controlled 6-month follow-up study conducted at Oulu University Hospital, Finland. Women with PCOS (Rotterdam criteria) were treated with atorvastatin (20 mg/d, n = 15) or placebo (n = 13) for 6 months. Fasting serum samples were collected at baseline and at 3 and 6 months. Oral and iv glucose tolerance tests were performed at 0 and 6 months. Androgen secretion and glucose metabolism were measured. Fasting levels and area under the curve of insulin increased significantly and insulin sensitivity (insulinogenic and Matsuda indexes) decreased during 6 months of atorvastatin therapy. Serum levels of dehydroepiandrosterone sulfate decreased in the atorvastatin group, whereas no change was observed in serum testosterone levels. Levels of C-reactive protein, total and low-density lipoprotein-cholesterol, and triglycerides decreased significantly during statin therapy. Atorvastatin therapy improves chronic inflammation and lipid profile, but it impairs insulin sensitivity in women with PCOS. Because women with PCOS have an increased risk of developing type 2 diabetes mellitus, the results suggest that statin therapy should be initiated on the basis of generally accepted criteria and individual risk assessment of cardiovascular disease, and not only because of PCOS.

The expression of FTO in human adipose tissue is influenced by fat depot, adiposity, and insulin sensitivity

The fat mass and obesity associated (FTO) gene is related to obesity, but the regulation of FTO expression in adipose tissue is not fully understood. We investigated FTO expression in paired subcutaneous and omental adipose tissues (SAT and OAT) from healthy women undergoing gynecological surgeries, and its relation with adiposity and insulin sensitivity. FTO expression in SAT of type 2 diabetic patients treated or not with Rosiglitazone was also compared. Both the mRNA and protein levels of FTO were higher in OAT from women than in SAT. Only OAT FTO protein levels negatively correlated with BMI and body fat mass, whereas SAT FTO mRNA levels were negatively correlated with subcutaneous fat deposition. In addition, SAT FTO mRNA and protein levels were increased in insulin resistant women (high HOMA) compared to insulin sensitive women (low HOMA), whereas OAT FTO expression was not different between these two subgroups. Interestingly, FTO mRNA levels were increased in SAT of type 2 diabetic patients, and treatment of diabetics with Rosiglitazone improved insulin sensitivity and reduced SAT FTO mRNA levels. Lastly, FTO expression was transiently increased in the early phase of 3T3-L1 cell differentiation, which coincides with the induction of PPARγ2 expression. However, partial reduction of FTO did not impact PPARγ2 expression and adipocyte differentiation. Therefore, FTO gene expression is higher in OAT than in SAT in lean to moderately obese women. OAT FTO expression is associated with adiposity, whereas SAT FTO expression is associated with insulin sensitivity. These associations are independent of an effect of FTO on adipocyte differentiation.

Favourable metabolic effects of a eucaloric lower‐carbohydrate diet in women with PCOS

Diet-induced reduction in circulating insulin may be an attractive nonpharmacological treatment for women with polycystic ovary syndrome (PCOS) among whom elevated insulin may exacerbate symptoms by stimulating testosterone synthesis. This study was designed to determine whether a modest reduction in dietary carbohydrate (CHO) content affects β-cell responsiveness, serum testosterone concentration and insulin sensitivity in women with PCOS. In a crossover design, two diets ('Standard,' STD, 55:18:27% energy from carbohydrate/protein/fat; lower-carbohydrate, 41:19:40) were provided for 8weeks in random order with a 4-week washout between. Thirty women with PCOS. β-cell responsiveness assessed as the C-peptide response to glucose during a liquid meal test; insulin sensitivity from insulin and glucose values throughout the test; insulin resistance (HOMA-IR); and total testosterone by immunoassay. Paired t-test indicated that the lower-CHO diet induced significant decreases in basal β-cell response (PhiB), fasting insulin, fasting glucose, HOMA-IR, total testosterone and all cholesterol measures, and significant increases in insulin sensitivity and dynamic ('first-phase') β-cell response. The STD diet induced a decrease in HDL-C and an increase in the total cholesterol-to-HDL-C ratio. Across all data combined, the change in testosterone was positively associated with the changes in fasting insulin, PhiB and insulin AUC (P<0·05). In women with PCOS, modest reduction in dietary CHO in the context of a weight-maintaining diet has numerous beneficial effects on the metabolic profile that may lead to a decrease in circulating testosterone.

Serum prolactin level is associated with insulin sensitivity in women of child-bearing age

To study the association between serum prolactin levels and insulin sensitivity in women of childbearing age in Eastern China.In the present study,211 women were enrolled and subdivided into normal weight group (n =40),overweight group (n =31),and obese group (n =140),according to the World Health Organization' s definition of obesity.All subjects received a standard 75 g oral glucose tolerance test.Insulin sensitivity index was assessed by the reduced sample number of Bergman's minimal model combined with intravenous glucose tolerance test.Serum prolactin levels in the overweight and obese subjects were significantly elevated when compared that in normal weight subjects(24.91 ng/ml,27.07 ng/ml vs 8.06 ng/ml,P＜0.01),but there was no significant difference between the levels in overweight and obese group(P =0.366).Multiple stepwise regression analysis showed that body mass index and insulin sensitivity index were independently associated with serum prolactin levels.Serum prolactin level is significantly associated with insulin sensitivity in women of child-bearing age. Key words: Women of child-bearing age; Prolactin; Obesity; Body mass index; Insulin sensitivity index

Impact of Cod Protein on Insulin Sensitivity in Women With Polycystic Ovary Syndrome

Impact of Cod Protein on Insulin Sensitivity in Women With Polycystic Ovary Syndrome

Adipokines, insulin-like growth factor binding protein-3 levels, and insulin sensitivity in women with polycystic ovary syndrome

Background/AimsMany women with polycystic ovary syndrome (PCOS) exhibit insulin resistance. Adipose tissue plays an important role in insulin resistance, and adipokines including tumor necrosis factor (TNF)-α and adiponectin are altered in PCOS. Insulin-like growth factor binding protein-3 (IGFBP-3), alone or in conjunction with other adipokines, is also associated with insulin resistance. We evaluated the effects of TNF-α, adiponectin, and IGFBP-3 on insulin sensitivity and the relationships among these proteins in women with PCOS.MethodsWe recruited 40 women with PCOS and 40 age- and body mass index (BMI)-matched regular cycling women (controls). The women were divided into obese (BMI ≥ 25 kg/m2) and nonobese (BMI < 25 kg/m2) groups. Anthropometric measurements were performed, and serum levels of TNF-α, adiponectin, and IGFBP-3 were determined. Insulin sensitivity was estimated using the metabolic clearance rate (MCR) of glucose calculated from the oral glucose tolerance test.ResultsSerum levels of TNF-α and IGFBP-3 did not differ between the PCOS and control groups, but adiponectin levels in the PCOS group were lower than those in control women in the nonobese group (p < 0.05). TNF-α, adiponectin, and IGFBP-3 levels were not correlated with each other in women with PCOS, but a significant positive correlation was observed between adiponectin levels and MCR (p < 0.05). Multiple regression analysis revealed that adiponectin levels were significantly associated with insulin sensitivity (p < 0.05) in women with PCOS.ConclusionsIGFBP-3 and TNF-α levels were not associated with insulin sensitivity, but adiponectin levels were related to insulin sensitivity in women with PCOS.

Moderate alcohol consumption is associated with improved insulin sensitivity, reduced basal insulin secretion rate and lower fasting glucagon concentration in healthy women

Moderate alcohol consumption is associated with a reduced risk of type 2 diabetes with a stronger effect in women. As the underlying mechanisms remain poorly characterised, we investigated its relationship with insulin resistance, insulin secretion, clearance of insulin and glucagon concentration. One-thousand two-hundred and seventy-six non-diabetic individuals from the RISC (relationship between insulin sensitivity and cardiovascular disease) study without high alcohol consumption were studied; all had a euglycaemic-hyperinsulinaemic clamp and an OGTT with assessment of insulin sensitivity, secretion and clearance. Alcohol consumption was positively associated with insulin sensitivity in women (β = 0.15, p ( trend ) = 0.005) and in men (β = 0.07, p ( trend ) = 0.07) after controlling for age, centre, waist, smoking and physical activity. In women, this association persisted after adjustment for adiponectin but was attenuated after controlling for HDL-cholesterol, suggesting that part of the protection is related to a higher HDL-cholesterol concentration. Higher alcohol consumption was associated with lower basal insulin secretion in women only (β = -0.10, p ( trend ) = 0.004) and this association persisted after adjustment for insulin sensitivity. In men, increasing alcohol consumption was associated with enhanced insulin clearance and increased fasting NEFA concentrations, independently of insulin sensitivity. Fasting glucagon decreased with increasing alcohol in women only (abstainers 9.2 ± 4.4; <28g/week 8.6 ± 4.0; 28-64g/week 8.1 ± 3.7; >64g/week 7.5 ± 3.1pmol/l; p ( trend ) = 0.01). Light-to-moderate alcohol consumption was associated in healthy women with enhanced insulin sensitivity, reduced basal insulin secretion rate and lower fasting plasma glucagon concentration, providing consistent mechanisms for the reduced risk of diabetes.

Statin therapy impairs insulin sensitivity in women with polycystic ovary syndrome (PCOS): a prospective, randomized, double-blinded, placebo-controlled study

Previous studies have suggested that women with PCOS may benefit from statin therapy as it has shown to decrease serum testosterone levels especially in subjects with hyperandrogenism. However, the data concerning the effects of statin therapy on glucose tolerance in PCOS have been controversial. The purpose of the present study was to explore the effects of atorvastatin therapy on glucose metabolism, androgens, lipid profile and chronic inflammation in women with PCOS.

Increase in subcutaneous adipose tissue and fat free mass in women with polycystic ovary syndrome is related to impaired insulin sensitivity

Objectives: The present study was performed to search whether subcutaneous and whole body adipose tissue increase and they relate to measures of insulin sensitivity in women with polycystic ovary syndrome (PCOS).Materials and methods: 52 women with PCOS and 53 healthy controls, all with similar age and body mass index participated in the study. A skinfold caliper device was used to measure biceps, triceps, subscapular and suprailiac skinfold thickness (SFT). Mid-upper arm circumference (MUAC) was measured using a tape measure. Body fat distributions were determined by bioelectrical impedance analysis. Insulin resistance score was computed with the HOMA formula. Plasma adiponectin was measured by EIA.Results: SFT in all defined areas, MUAC, total body and trunk fat free mass, and HOMA score were higher in women with PCOS compared with healthy women, while adiponectin level was significantly lower. SFT values correlated positively with HOMA score, and negatively with blood adiponectin level. Regression analysis indicated, SFT in triceps and supscapular areas, trunk fat mass, trunk fat ratio, fat free mass and trunk fat free mass values as the most powerful predictors of HOMA score.Conclusions: The present study showed that SFT in different body regions and fat-free tissue mass are increased in women with PCOS, with a significant relation to impaired insulin sensitivity.

Insulin Resistant Phenotype of Polycystic Ovary Syndrome does not Seem to be Caused by Variation in FTO

Genetic variation in the FTO gene is associated with increased body weight and reduced insulin sensitivity. We investigated whether genetic variation in FTO is associated with polycystic ovary syndrome (PCOS), a condition also characterized by insulin resistance. Furthermore, we tested whether insulin resistance is specifically associated with genetic variation in FTO in women with PCOS. Sixty-two nondiabetic patients with PCOS defined by the Rotterdam criteria were compared to BMI and age-matched women. Each PCOS case was matched to 2 controls. All participants underwent an oral glucose tolerance test and were genotyped for the single nucleotide polymorphism rs8050136 in the FTO gene. There was no difference in the frequency of FTO genotypes between the PCOS and the non-PCOS groups. In non-PCOS participants, genetic variation in FTO is associated with insulin sensitivity (p=0.03). This association remained significant after adjustment for age and/or BMI (p<= 0.03). In subjects with PCOS, however, FTO did not associate with insulin sensitivity (p=0.67). Genetic variation in FTO does not have an impact on insulin sensitivity in women with PCOS and is therefore not involved in the pathogenesis of the insulin resistant phenotype seen in patients with PCOS.

Impact of the FTO gene variation on fat oxidation and its potential influence on body weight in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder where insulin resistance might be involved in the development of endocrine and metabolic abnormalities. It has recently been shown that the FTO gene modifies weight, fat mass and insulin sensitivity in women with PCOS, where its role might be larger than in other phenotypes. The aim of this study was to estimate the effect of a variation of the FTO gene on carbohydrate and lipid oxidation in PCOS women. The study group consisted of 65 women with PCOS and 28 healthy, normally menstruating women. Clinical examination, anthropometric measurements, euglycaemic hyperinsulinaemic clamp and measurements of serum sex hormones were performed. Carbohydrate and lipid oxidation were evaluated with indirect calorimetry in the baseline state and during last 30 min of the clamp. The FTO rs9939609 polymorphism was genotyped using the restriction fragment length polymorphism method. There were no differences in carbohydrate and lipid oxidation between PCOS and control women. In the PCOS group, TT homozygotes had higher baseline fat oxidation in comparison with carriers of the A allele (P = 0·018), which was not found in the control group. We did not observe the effect of the FTO gene variation on insulin-stimulated lipid oxidation and neither on the baseline nor on the insulin-stimulated carbohydrate oxidation. Our data show that this FTO gene variation might influence the baseline lipid oxidation in PCOS patients. This might potentially be one of the mechanisms explaining the impact of the FTO gene on body weight in PCOS.

Diverging sex-specific long-term effects of cigarette smoking on fasting insulin and glucose levels in non-diabetic people

ObjectivesWe determined in non-diabetic persons the associations of current smoking with future glucose and insulin concentrations. Design and methodsMiddle-aged non-diabetic adults (n=1071) were studied in whom these values were measured at baseline and 5.2-years later. ResultsAge-adjusted fasting insulin concentrations in 137 smoking men remained lower than never smokers at both surveys. While age-adjusted fasting glucose values in male never smokers declined at follow-up (p=0.037), they rose in male smokers. In 94 female smokers, age-adjusted fasting insulin values marginally declined, and fasting glucose was reduced (by 0.09mmol/L, p=0.055) during follow-up. In contrast in never-smoking women, insulin and glucose concentrations rose (p<0.001 in both). Age-adjusted insulin levels in former smokers exhibited similar trends as never smokers. Trends were essentially unchanged when adjustment included body mass index. Current male smokers demonstrated evidence of reduced insulin sensitivity, female smokers of improved one, as assessed by QUICKI. ConclusionSmoking among Turks induces at long-term lower fasting insulin levels which represent improved insulin sensitivity in women, yet a reduced one in men.

Evidence that the association between exercise intensity and insulin sensitivity is sex dependent

The purpose of this study was to determine if, after adjusting for the contribution of exercise dose, exercise intensity was associated with the improvement of insulin sensitivity. Abdominally obese, sedentary men (n = 16, (mean ± SD) age 45.0 ± 7.5 years, waist circumference 108.6 ± 5.3 cm) and women (n = 18, (mean ± SD) age 42.3 ± 6.2 years, waist circumference 100.1 ± 8.2 cm) performed daily, supervised exercise for 3 and 4 months, respectively. Exercising at a self-selected exercise intensity, men were required to expend 700 kcal per session and women 500 kcal per session. Exercise intensity and dose were determined using heart rate and oxygen consumption data obtained from repeated graded exercise tests. Insulin sensitivity was determined by hyperinsulinemic euglycemic clamp. Insulin sensitivity improved in both men and women (change scores: men 7.2 ± 5.4 mg·(kg skeletal muscle (skm))(-1)·min(-1); women 5.8 ± 7.1 mg·(kg skm)(-1)·min(-1); p < 0.05). Exercise intensity was associated with the improvement of insulin sensitivity in men (unstandardized regression coefficient (β) = 0.43, p = 0.02). Adjusting for exercise dose, total abdominal adipose tissue (AT), or visceral AT did not alter this association (p < 0.05). Exercise intensity was not associated with the improvement of insulin sensitivity in women (β = -0.11, p = 0.7). Adjusting for exercise dose, total abdominal AT, or visceral AT did not change this association in women (p > 0.05). Our findings suggest that exercise intensity is independently associated with the improvement of insulin sensitivity in abdominally obese men but not women.

Myocardial steatosis, cardiac remodelling and fitness in insulin-sensitive and insulin-resistant obese women

BackgroundObesity predisposes to heart failure and premature cardiovascular death, particularly in sedentary women. In animal models and in men with type 2 diabetes mellitus, impaired cardiac function is associated with...

8 - Implication of adipose tissue (pro)renin receptor in the development of obesity

| 141 preadipocytes in the presence of LDL (1.4 g/L) decreased preadipocytes differentiation, evident by smaller lipid droplets and decreased adipocytes in situ lipoprotein lipase activity (i.e., decreased hydrolysis and storage of synthetic 3H-triglyceride rich lipoproteins by adipocytes) (-31%, p=0.04). Moreover, acute exposure of mature 3T3-L1 adipocytes to LDL inhibited in situ lipoprotein lipase activity (up to -30%, six hours). Ex vivo: Similarly, the efficiency of FA trapping in post-menopausal women WAT biopsies was measured as the clearance and storage of synthetic 3H-triglyceride rich lipoproteins and of albumin-bound 3H-FA. Four hours exposure to LDL (apoB=1.2 g/L) increased the accumulation of 3H-triglyceride rich lipoproteins (by 75 ± 32%, p=0.04) and of 3HFA (by 121 ± 24%, p=0.008) in the medium, indicating reduced FA trapping in WAT. conclusion: LDL decreases differentiation and FA trapping in 3T3L1 adipocytes and in WAT of post-menopausal obese women. These novel findings may explain decreased insulin sensitivity in women with hyperapoB.