Individual Metabolic Variables Research Articles

Perspective: Novel Approaches to Evaluate Dietary Quality: Combining Methods to Enhance Measurement for Dietary Surveillance and Interventions

Refining existing dietary assessment methods to reduce measurement error and facilitate the routine evaluation of dietary quality is essential to inform health policy. Notable advancements in technology in the past decade have enhanced the precision and transformation of dietary assessment methods with applications toward both population health and precision nutrition. Within population health, innovative applications of big data including use of automatically collected food purchasing data, quantitative measurement of food environments, and novel, yet simplified dietary quality metrics provide important complementary data to traditional self-report methods. Precision nutrition is similarly advancing with greater use of validated biomarkers for assessing dietary patterns and understanding individual variability in metabolism. Concurrently enhancing our understanding of diet-disease relations at the population health and precision nutrition levels provides tremendous potential to generate evidence needed to advance public health nutrition policy. This commentary highlights the importance of these advances toward progressing the field of dietary assessment and discusses the application of food purchasing data, data analytics, alternative dietary quality metrics, and -omics technology in population and clinical medicine.

Cognitive performance in patients with bipolar disorder and metabolic syndrome

ObjectiveTo describe and discuss current evidence on the relationship between cognitive performance, bipolar affective disorder (BAD) and metabolic syndrome (MS). MethodsWe searched for related articles in different bibliographic databases (MEDLINE, EMBASE, Scielo) and performed a narrative review of the literature with the selected articles. ResultsTo date, evidence has not been conclusive and the effect of MS on BD has not been widely studied, but important correlations have been observed with individual metabolic variables. It is suggested that obesity in patients with BAD is associated with worse performance in verbal memory, psychomotor processing speed, and sustained attention. Hypertriglyceridemia in patients with BAD appears to be associated with a lower score in executive function tasks; hypertension appears to be associated with impairment in overall cognitive function. ConclusionsDespite the associations between MS and poor cognitive performance in patients suffering from BAD, more studies are required to precisely determine how these variables are related to each other.

Desempeño cognitivo de los pacientes con trastorno afectivo bipolar y síndrome metabólico

ObjectiveTo describe and discuss current evidence on the relationship between cognitive performance, Bipolar Affective Disorder (BAD) and Metabolic Syndrome (MS). MethodsWe searched for related articles in different bibliographic databases (MEDLINE, EMBASE, Scielo) and performed a narrative review of the literature with the selected articles. ResultsTo date, evidence has not been conclusive and the effect of MS on BD has not been widely studied, but important correlations have been observed with individual metabolic variables. It is suggested that obesity in patients with BAD is associated wotj worse performance in verbal memory, psychomotor processing speed, and sustained attention. Hypertriglyceridemia in patients with BAD appears to be associated with a lower score in executive function tasks; hypertension appears to be associated with impairment in overall cognitive function. ConclusionsDespite the associations between MS and poor cognitive performance in patients suffering from BAD, more studies are required to precisely determine how these variables are related to each other.

Development of a method of clozapine dosage by selective electrode to the iodides

Clozapine (Leponex®), the main neuroleptic indicated in the treatment of resistant schizophrenia, requires therapeutic monitoring because of its side effects and the individual variability in metabolism. In addition, several cases of intoxication by this drug were described in the literature. In this work, we studied the indirect dosage of clozapine by selective electrode to the iodides for the optimization of an analytical protocol allowing therapeutic monitoring and the diagnosis of intoxication and/or overdose. Our results showed that the developed method is linear between 0.05 and 12.5 µg/mL (r = 0.980), with a limit of detection of 0.645.10−3 µg/mL. It presents good precision (coefficient of variation less than 4%) and accuracy (coefficient less than 10%) for all the studied concentrations. With a domain of linearity covering a wide margin of concentrations, this method can be applicable to the dosage of clozapine in tablets and in different biological matrices, such as plasma, urines, and postmortem samples.

The clustering patterns of metabolic risk factors and its association with sub-clinical atherosclerosis in Korean population

Background and aims: Metabolic syndrome (MetS) is considered to be an insulin-resistance syndrome, but recent evidence suggests that MetS has multiple physiological origins which may be related to atherosclerosis. This study investigated clustering patterns of metabolic risk factors and its association with sub-clinical atherosclerosis.Subjects and methods: This study used factor analysis of 11 metabolic factors in 1374 individuals to define clustering patterns and determine their association with carotid intima-media thickness (CIMT). Eleven metabolic factors were used: body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), fasting blood insulin (FBI), serum triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), homeostasis model assessment-insulin resistance (HOMA-IR), high-sensitivity C-reactive protein (hsCRP) and adiponectin. Two regression analyses were done, the first using individual metabolic variables and the second using each factor from the factor analysis to evaluate their relationships with CIMT.Results: Four clustering patterns, insulin-resistance factor (FBG, FBI, HOMA-IR), obesity-inflammatory factor (BMI, WC, hsCRP), blood pressure factor (SBP, DBP) and lipid metabolic factor (HDL-C, TG, adiponectin) were categorized. In a multivariate regression model after adjustment for age, sex, low-density lipoprotein cholesterol and smoking history (pack year), insulin resistance factor (B = 11.09, p = 0.026), obesity-inflammatory factor (B = 18.50, p < 0.001), blood pressure factor (B = 12.84, p = 0.010) and lipid metabolic factor (B = − 11.55, p = 0.023) were found to be significantly associated with CIMT.Conclusion: In conclusion, metabolic risk factors have four distinct clustering patterns that are independently associated with sub-clinical atherosclerosis.

Steroids in kidney transplant patients

Any evaluation of steroids in kidney transplantation is hampered by individual variability in metabolism, the lack of clinically available steroid blood levels, and overall little attention to steroid exposure. Many feel that steroids were an essential part of chronic immunosuppression in past decades but may no longer be necessary in low-risk populations when our newer and more potent drugs are used. Potential differences in long-term outcome will be unapparent in short-term antibody induction studies in low-risk patients, particularly with low on steroid doses, as may have happened in the recent, well-done Astellas trial. In many studies, the evidence for the superiority of mycophenolate (MMF) and tacrolimus (TAC) was not as strong as the evidence for the benefit of steroids in the Canadian cyclosporine study. As the practice of steroid withdrawal has increased, we have not seen the improvement in long-term graft survival that many expected with our newer agents. Steroids have immunosuppressive effects even in doses that are low by historic standards, and side effects may not justify their abandonment.

Causes of Different Estimates of the Prevalence of Metabolic Syndrome in Korea

Background/AimsReports of the prevalence of and trends in metabolic syndrome in Korea have been inconsistent. Thus, we investigated the reasons underlying these inconsistencies.MethodsWe estimated the prevalence of metabolic syndrome using different diagnostic criteria, exclusion criteria, and sampling weights among 5,509 respondents, aged 20-79, who participated in the 2001 Korean National Health and Nutrition Examination Surveys (KNHANES). Trends in metabolic syndrome were assessed by examining the 1998 (n = 6,747), 2001 (n = 4,337), and 2005 (n = 5,139) KNHANES.ResultsThe estimated prevalence of metabolic syndrome in 2001 ranged from 1.6 to 29.6% in males and from 10.1 to 32.8% in females, depending on the diagnostic criteria used. The exclusion criteria and sampling weights did not significantly affect the prevalence estimates. The prevalence of metabolic syndrome first significantly increased and then decreased between 1998, 2001, and 2005 in males (26.2, 29.6, and 27.2%, respectively) and females (29.2, 32.8, and 24.7%, respectively). Among the individual metabolic variables, triglyceride levels in 2001 were significantly higher than in 1998 and 2005, whereas other variables remained relatively constant during the same period. The exceptionally high triglyceride levels in 2001 might have contributed to the increased prevalence of metabolic syndrome between 1998 and 2001.ConclusionsDifferent diagnostic criteria for metabolic syndrome represent a major cause of the inconsistent estimates of prevalence, and the absence of standardized laboratory methods might have affected the trend estimates.

Sustained participation in youth sport decreases metabolic syndrome in adulthood

to explore the effect of organized youth sport on metabolic syndrome (MetS) in adulthood. Longitudinal study data from the cardiovascular risk in young Finns study. A total of 1493 males (n=704) and females (n=789) aged 3, 6, 9, 12, 15 and 18 years were randomly selected from five university towns and their rural surroundings in 1980. They were followed up for 21 years. In 2001 they were 24, 27, 30, 33, 36 and 39 years old. Youth sports participation data (participation in sport-club training and competitions) were assessed in 1980 and 1983 using a self-report questionnaire completed in connection with a medical examination. Participants were divided into athletes and non-athletes at each measurement point, and then classified into four groups: Persistent athlete, Starter, Leaver and Non-athlete. A mean score of youth sport was assessed by calculating the average of four consecutive measurements (1980-1989). MetS risk in 2001 was defined as a categorical variable based on the guidelines of the European Group for the Study of Insulin Resistance (EGIR) and as a continuous MetS-score variable by summing the z-scores of individual metabolic variables. In males and females, intense participation in youth sports over 3 years was inversely and significantly associated with clustered MetS score and prevalence of MetS defined by EGIR in adulthood (P<0.05). The association remained significant after adjustment for age, baseline clustered MetS score, smoking and total caloric intake and after additional adjustments for adult leisure-time physical activity. Starters during 3 years were less likely to have MetS than non-athletes. Leavers were at a higher risk for MetS than persistent athletes. These associations were attenuated in males by adjustment for all potential confounders. Similar associations were found using EGIR MetS as an outcome. Sustained participation in organized sport lasting at least 3 years in youth is associated with reduced risk for developing MetS in adulthood.

Reply:

We thank Drs. Dogru and Teoman for their interesting comments regarding our recent article on the importance of visceral fat to the pathogenesis of nonalcoholic steatohepatitis.1 Our study showed visceral fat to be a key mediator of steatohepatitis independent of insulin resistance and importantly, independent of a diagnosis of metabolic syndrome (MetS). We agree that all components of the MetS can variably be associated with both insulin levels and those of circulating adipokines. However, the MetS (as defined by various criteria) has been developed purely for operational reasons. This syndrome is the consequence, rather than the cause of metabolic dysregulation. For this reason, in our multivariate analysis, we controlled the effects of visceral fat for both circulating adipokines and insulin sensitivity as measured by the homeostasis model assessment of insulin resistance (HOMA-IR). The HOMA-IR has been shown to correlate well with the results of the euglycemic-hyperinsulinemic clamp in patients with and without type 2 diabetes, even in the presence of metformin or sulfonylureas.2, 3 Thus, any confounding effect of MetS components, or indeed the medications used to treat these components, will have been reflected and controlled for by HOMA-IR levels and those of the circulating adipokines. We are happy to provide some additional results that clarify the relationship between visceral fat and the other components of the MetS (Table 1). These demonstrate that the most marked changes in visceral fat occur with increasing dysregulation of glucose handling, while those associated with dyslipidemia and hypertension did not reach statistical significance. When the association between these individual metabolic variables and necroinflammation and fibrosis in nonalcoholic steatohepatitis was considered, only MetS glucose (P = 0.04) was significant, while elevated blood pressure (P = 0.35), elevated triglycerides (P = 0.9), and low high-density lipoprotein (P = 0. 13) were not associated. Given that we have already specifically controlled for the effects of insulin sensitivity, we did not further analyze the data. David van der Poorten*, Jacob George*, * Storr Liver Unit, Westmead Millennium Institute, University of Sydney, Westmead, NSW, Australia.

Antioxidant status and hearing function in noise-exposed workers

The cellular antioxidant system appears to protect cochlear hair cells from oxidative stress due to noise and aging. The role of individual metabolic variables remains poorly understood, however. We examined the role of a number of metabolic factors on human cochlear function in noise-exposed individuals. In 58 factory workers we measured audiometry and distortion product otoacoustic emissions prior to a workshift. Simultaneously we measured levels of vitamin E, vitamin C, and polymorphism status for two metabolic genes related to glutathione S-transferase function (GSTM1 and GSTT1). Age and total noise exposure were predictive of hearing status. Vitamin E levels were negatively correlated with hearing function, and this effect was partly explained by an increase in vitamin E levels with age. No effect was found for vitamin C. Individuals possessing the GSTM1 gene had significantly better high frequency otoacoustic emissions compared to GSTM1 null individuals. The protective effect of GSTM1 was present even after adjusting for age, race, sex, and years of noise exposure. GSTT1 did not exhibit a similarly protective effect. While the cross-sectional nature of the study precludes drawing conclusions about causation, these data suggest that GSTM1, an antioxidant enzyme which is found in the mammalian cochlea, may play a protective role in humans against hair cell damage due to noise or aging.