Insulin resistance, beta cell dysfunction and visceral adiposity as predictors of incident diabetes: the Insulin Resistance Atherosclerosis Study (IRAS) Family study

Change in abdominal obesity after colon cancer surgery - effects of left-sided and right-sided colonic resection

BACKGROUND

Excess abdominal visceral adipose tissue (VAT) is associated with metabolic diseases and poor survival in colon cancer (CC). We assessed the impact of different types of CC surgery on changes in abdominal fat depots.

MATERIAL AND METHODS

Computed tomography (CT)-scans performed preoperative and 3 years after CC surgery were analyzed at L3-level for VAT, subcutaneous adipose tissue (SAT) and total adipose tissue (TAT) areas. We assessed changes in VAT, SAT, TAT and VAT/SAT ratio after 3 years and compared the changes between patients who had undergone left-sided and right-sided colonic resection in the total population and in men and women separately.

RESULTS

A total of 134 patients with stage I-III CC undergoing cancer surgery were included. Patients who had undergone left-sided colonic resection had after 3 years follow-up a 5% (95% CI: 2-9%, p < 0.01) increase in abdominal VAT, a 4% (95% CI: 2-6%, p < 0.001) increase in SAT and a 5% increase (95% CI: 2-7%, p < 0.01) in TAT. Patients who had undergone right-sided colonic resection had no change in VAT, but a 6% (95% CI: 4-9%, p < 0.001) increase in SAT and a 4% (95% CI: 1-7%, p < 0.01) increase in TAT after 3 years. Stratified by sex, only males undergoing left-sided colonic resection had a significant VAT increase of 6% (95% CI: 2-10%, p < 0.01) after 3 years.

CONCLUSION

After 3 years follow-up survivors of CC accumulated abdominal adipose tissue. Notably, those who underwent left-sided colonic resection had increased VAT and SAT, whereas those who underwent right-sided colonic resection demonstrated solely increased SAT.

Cardiometabolic disease in Black African and Caribbean populations: an ethnic divergence in pathophysiology?

In the UK, populations of Black African and Caribbean (BAC) ethnicity suffer higher rates of cardiometabolic disease than White Europeans (WE). Obesity, leading to increased visceral adipose tissue (VAT) and intrahepatic lipid (IHL), has long been associated with cardiometabolic risk, driving insulin resistance and defective fatty acid/lipoprotein metabolism. These defects are compounded by a state of chronic low-grade inflammation, driven by dysfunctional adipose tissue. Emerging evidence has highlighted associations between central complement system components and adipose tissue, fatty acid metabolism and inflammation; it may therefore sit at the intersection of various cardiometabolic disease risk factors. However, increasing evidence suggests an ethnic divergence in pathophysiology, whereby current theories fail to explain the high rates of cardiometabolic disease in BAC populations. Lower fasting and postprandial TAG has been reported in BAC, alongside lower VAT and IHL deposition, which are paradoxical to the high rates of cardiometabolic disease exhibited by this ethnic group. Furthermore, BAC have been shown to exhibit a more anti-inflammatory profile, with lower TNF-α and greater IL-10. In contrast, recent evidence has revealed greater complement activation in BAC compared to WE, suggesting its dysregulation may play a greater role in the high rates of cardiometabolic disease experienced by this population. This review outlines the current theories of how obesity is proposed to drive cardiometabolic disease, before discussing evidence for ethnic differences in disease pathophysiology between BAC and WE populations.

Deteriorating beta cell function is the dominant determinant of progression from normal glucose tolerance to prediabetes/diabetes in young women following pregnancy

AIMS/HYPOTHESIS

Excess adiposity, insulin resistance and beta cell dysfunction each contribute to the development of prediabetes (impaired glucose tolerance and/or impaired fasting glucose)/diabetes but their comparative impact in relation to one another remains uncertain. We thus ranked their contributions to incident dysglycaemia over the first 5 years postpartum in women reflecting the full spectrum of gestational glucose tolerance (spanning normoglycaemia to gestational diabetes) and hence a range of future diabetic risk.

METHODS

In this study, 302 women with normal glucose tolerance (NGT) on OGTT at 3 months postpartum underwent repeat OGTT at 1 year, 3 years and 5 years, enabling serial assessment of glucose tolerance, insulin sensitivity/resistance (Matsuda index, HOMA-IR) and beta cell function (insulin secretion-sensitivity index-2 [ISSI-2], insulinogenic index [IGI]/HOMA-IR). Determinants of prediabetes/diabetes were ranked by change in concordance index (CCI) of Cox proportional hazard regression models.

RESULTS

Over 5 years of follow-up, 89 women progressed from NGT to prediabetes/diabetes (progressors). At 3 months postpartum, though all women were normoglycaemic, future progressors had higher fasting glucose (p=0.03) and 2 h glucose (p<0.0001) than non-progressors, coupled with higher BMI (p=0.001), greater insulin resistance (both Matsuda index and HOMA-IR, p≤0.02) and poorer beta cell function (both ISSI-2 and IGI/HOMA-IR, p≤0.006). Unlike their peers, progressors exhibited deteriorating beta cell function from 1 year to 5 years (both p<0.0001). On regression analyses, the dominant determinants of progression to prediabetes/diabetes were time-varying ISSI-2 (change in CCI 25.2%) and IGI/HOMA-IR (13.0%), in contrast to time-varying Matsuda index (2.9%) and HOMA-IR (0.5%). Neither time-varying BMI nor waist were significant predictors after adjustment for beta cell function and insulin sensitivity/resistance.

CONCLUSION/INTERPRETATION

Declining beta cell function is the dominant determinant of incident prediabetes/diabetes in young women following pregnancy.

Impact of saturated compared with unsaturated dietary fat on insulin sensitivity, pancreatic β-cell function and glucose tolerance: a systematic review and meta-analysis of randomized, controlled trials

BACKGROUND

The impact of the dietary fat type on type 2 diabetes (T2D) remains unclear.

OBJECTIVES

We aimed to evaluate the effects of replacing dietary saturated fatty acids (SFA) with mono- or poly-unsaturated fatty acids (MUFA and PUFA, respectively) on insulin sensitivity, pancreatic β-cell function, and glucose tolerance, as surrogate endpoints for T2D.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials that replaced ≥5% of total energy intake provided by SFA with MUFA or PUFA and reported indexes of insulin sensitivity, β-cell function, and/or glucose tolerance. We searched MEDLINE, Scopus, and the Cochrane Library (CENTRAL) up to 9 January, 2023. Eligible interventions had to be isocaloric, with no significant difference in other macronutrients. Data were synthesized using random-effects model meta-analysis.

RESULTS

Of 6355 records identified, 10 parallel and 20 crossover trials with 1586 participants were included. The mean age of the participants was 42 years, 47% were male, mean body mass index (BMI; in kg/m2) was 26.8, median baseline fasting glucose was 5.13 mmol/L, and the median duration of interventions was 5 weeks. Replacing SFA with MUFA or PUFA had no significant effects on insulin sensitivity [standardized mean difference (SMD) SFA compared with MUFA: 0.01, 95% confidence interval (CI): -0.06 to 0.09, I2 = 0% and SMD SFA compared with PUFA: 0, 95% CI: -0.15 to 0.14, I2 = 0%]. Replacing SFA with MUFA did not significantly impact the β-cell function, evaluated by the disposition index (mean difference: -12, 95% CI: -158 to 133, I2=0%). Evidence on glucose tolerance (SFA compared with MUFA or PUFA) and on β-cell function when SFA were replaced with PUFA was scant.

CONCLUSIONS

Short-term substitution of saturated with unsaturated fat does not significantly affect insulin sensitivity nor β-cell function (the latter in the SFA compared with MUFA comparison). Future studies are needed to elucidate longer term effects of dietary fat saturation on glucose homeostasis. This trial was registered at PROSPERO as CRD42020178382.

Reinstating acute-phase insulin release among sedentary adults at high risk for type 2 diabetes with Yoga and Walking based lifestyle modification

BACKGROUND

We compared the impact of 2 lifestyle modifying physical activities, yoga (YBLM) or walking (WBLM) on impaired beta cell function (IBF) or insulin resistance (IR) in restoring acute phase insulin release (APIR) among prediabetes at high risk for type 2 diabetes (HRDM).

METHOD

Male and female adults (N = 42, 38.1 ± 4.8 years) with abdominal obesity (Male:103 ± 8.1 cm) Female: 92 ± 11.1 cm), randomized into YBLM (n = 20) and WBLM (n = 22), were monitored for the practice of the intervention, 45 min a day/5 days a week for 12 weeks. Blood sample was collected at 0th minute to estimate the level of Fasting Blood Glucose (FBG), Sr. Insulin and lipid profile and at 10th minute (APIR). IBF, IR and sensitivity (IS) reading were checked in HOMA-2 calculator.

RESULT

Wilcoxon sign rank t-test denoted an improved APIR among the subjects with IBF (p = 0.008) and not among the subjects with IR (p = 0.332). However, regression analysis yielded an improved APIR among subjects with IBF (F(1,10) = 7.816, p = 0.002) with the management of body weight and lipid profile and IR (F(1,13) = 17.003, p = 0.001) being found influenced with selected lipid components. In all, during the post assessment period, an impressive boost in APIR was manifested among people shifted to Normoglycemia (n = 14, 35.9%).

CONCLUSION

Intriguingly, we postulate the potential role of YBLM over WBLM in the management of lipid profile and body weight on accelerating APIR either through improved Beta cell compensation or by sensitizing skeletal muscles regulating IR, helping improve glucose tolerance resulting in either remission or management of prediabetes.

Secular trend of non-communicable chronic disease prevalence throughout the life span who endured Chinese Great Famine (1959-1961)

BACKGROUND

Famine is a risk factor for non-communicable chronic diseases (NCDs), which account for over 80% of deaths in China. The effect of famine on the prevalence of NCDs in terms of various age groups, time periods and cohorts is currently poorly understood.

OBJECTIVE

This study aims to explore long-term trends in the impact of China's Great Famine (1959-1961) on NCDs in China.

METHODS

This study used data from the 2010-2020 China Family Panel Longitudinal Survey across 25 provinces in China. The subjects were aged 18-85 years, and the total number of subjects was 174,894. The prevalence of NCDs was derived from the China Family Panel Studies database (CFPS). An age-period-cohort (APC) model was used to estimate the age, period and cohort effects of NCDs in 2010-2020 and the effect of famine on the risk of NCDs in terms of cohort effects.

RESULTS

The prevalence of NCDs increased with age. Additionally, the prevalence did not clearly decrease over the survey period. Regarding the cohort effect, people born in the years adjacent to the famine period had a higher risk of NCDs; additionally, females, those born in rural areas, and those who lived in provinces with severe famine and post-famine had a higher likelihood of NCDs.

CONCLUSIONS

Experiencing famine at an early age or the experience of famine in a close relative's generation (births after the onset of famine) are associated with an increased risk of NCDs. Additionally, more severe famine is associated with a higher risk of NCDs.

Sex differences in body composition in people with prediabetes and type 2 diabetes as compared with people with normal glucose metabolism: the Maastricht Study

AIMS/HYPOTHESIS

Obesity is a major risk factor for type 2 diabetes. However, body composition differs between women and men. In this study we investigate the association between diabetes status and body composition and whether this association is moderated by sex.

METHODS

In a population-based cohort study (n=7639; age 40-75 years, 50% women, 25% type 2 diabetes), we estimated the sex-specific associations, and differences therein, of prediabetes (i.e. impaired fasting glucose and/or impaired glucose tolerance) and type 2 diabetes (reference: normal glucose metabolism [NGM]) with dual-energy x-ray absorptiometry (DEXA)- and MRI-derived measures of body composition and with hip circumference. Sex differences were analysed using adjusted regression models with interaction terms of sex-by-diabetes status.

RESULTS

Compared with their NGM counterparts, both women and men with prediabetes and type 2 diabetes had more fat and lean mass and a greater hip circumference. The differences in subcutaneous adipose tissue, hip circumference and total and peripheral lean mass between type 2 diabetes and NGM were greater in women than men (women minus men [W-M] mean difference [95% CI]: 15.0 cm2 [1.5, 28.5], 3.2 cm [2.2, 4.1], 690 g [8, 1372] and 443 g [142, 744], respectively). The difference in visceral adipose tissue between type 2 diabetes and NGM was greater in men than women (W-M mean difference [95% CI]: -14.8 cm2 [-26.4, -3.1]). There was no sex difference in the percentage of liver fat between type 2 diabetes and NGM. The differences in measures of body composition between prediabetes and NGM were generally in the same direction, but were not significantly different between women and men.

CONCLUSIONS/INTERPRETATION

This study indicates that there are sex differences in body composition associated with type 2 diabetes. The pathophysiological significance of these sex-associated differences requires further study.

Modifiable predictors of type 2 diabetes mellitus and roles of insulin resistance and β-cell function over a 6-year study and 30-year follow-up

PURPOSE

This study aimed to examine the modifiable predictors of T2DM and the roles of insulin resistance (IR) and β-cell function over a 6-year study and 30-year follow-up.

METHODS

A total of 462 non-diabetic participants, 282 with impaired glucose tolerance (IGT), and 180 with normal glucose tolerance (NGT) were enrolled in this analysis. The Matsuda IR index and area under the curve of insulin-to-glucose ratio (AUCI/G-R) were used as IR and β-cell function indices in the analysis.

RESULTS

In all participants, multivariable analysis showed that BMI, glucose status, Matsuda IR index and systolic blood pressure (SBP) at baseline were independently associated with an increased risk of T2DM over 30 years, whereas lifestyle intervention and AUCI/G-R were inversely associated with this risk. The predictive effect of the Matsuda IR index and AUCI/G-R in participants with IGT was consistent with the results of all participants, whereas in those with NGT, only the Matsuda IR index, not the AUCI/G-R, predicted the development of T2DM (HR = 1.42, 95% CI 1.07-1.89 vs HR = 1.09, 95% CI 0.76-1.56). The predictive effect of the Matsuda IR index on T2DM existed even in participants with BMI < 25 (p = 0.049).

CONCLUSION

The modifiable predictors of T2DM in Chinese adults were high BMI, hypertension, mild hyperglycaemia, IR, and β-cell dysfunction. Both IR and β-cell function contributed to the development of T2DM in the long term; however, IR remains the initial and long-standing key risk factor for T2DM.

Cumulative exposure to metabolic syndrome in a national population-based cohort of young adults and sex-specific risk for type 2 diabetes

BACKGROUND

Metabolic syndrome is associated with type 2 diabetes and its prevalence is increasing worldwide in young adults. We aimed to determine whether cumulative exposure to metabolic syndrome is associated with type 2 diabetes risk in young adults.

METHODS

Data of 1,376,540 participants aged 20-39 years without a history of type 2 diabetes and who underwent four annual health check-ups were collected. In this large-scale prospective cohort study, we evaluated the incidence rates and hazard ratios (HRs) of diabetes according to cumulative frequencies of metabolic syndrome over 4 years of consecutive annual health check-ups (burden score 0-4). Subgroup analyses were performed by sex and age.

RESULTS

During 5.18 years of follow-up, 18,155 young adults developed type 2 diabetes. The incidence of type 2 diabetes increased with burden score (P < 0.0001). The multivariable-adjusted HRs for type 2 diabetes were 4.757, 10.511, 18.288, and 31.749 in participants with a burden score of 1 to 4, respectively, compared to those with 0. In subgroup analyses, the risk of incident diabetes was greater in women than men and in the 20-29 years age group than the 30-39 years age group. The HRs were 47.473 in women and 27.852 in men with four burden scores.

CONCLUSION

The risk of type 2 diabetes significantly increased with an increase in the cumulative burden of metabolic syndrome in young adults. Additionally, the association between cumulative burden and diabetes risk was stronger in women and the 20s age group.

Long-term Outcome of Body Composition, Ectopic Lipid, and Insulin Resistance Changes With Surgical Treatment of Acromegaly

Context

Acromegaly presents a unique pattern of lower adiposity and insulin resistance in active disease but reduction in insulin resistance despite a rise in adiposity after surgery. Depot-specific adipose tissue masses and ectopic lipid are important predictors of insulin resistance in other populations, but whether they are in acromegaly is unknown. Long-term persistence of body composition changes after surgery is unknown.

Objective

To determine how depot-specific body composition and ectopic lipid relate to insulin resistance in active acromegaly and whether their changes with surgery are sustained long-term.

Methods

Cross-sectional study in patients with active acromegaly and longitudinal study in newly diagnosed patients studied before and in long-term follow-up, 3 (1-8) years (median, range), after surgery. Seventy-one patients with active acromegaly studied cross-sectionally and 28 with newly diagnosed acromegaly studied longitudinally. Main outcome measures were visceral (VAT), subcutaneous (SAT), and intermuscular adipose tissue masses by whole-body magnetic resonance imaging; intrahepatic lipid (IHL) by proton magnetic resonance spectroscopy; insulin resistance measures derived from fasting; and oral glucose tolerance test insulin and glucose levels.

Results

SAT and insulin-like growth factor 1 level, but not VAT or IHL, were independent predictors of insulin resistance in active acromegaly. VAT, SAT, and IHL gains were sustained long-term after surgery. VAT mass rise with surgery correlated inversely with rise in QUICKI while SAT rise correlated with fall in the Homeostatic Model Assessment score.

Conclusion

SAT and disease activity are important predictors of insulin resistance in active acromegaly. Adiposity gains are sustained long-term after surgical treatment and impact on the accompanying improvement in insulin resistance.

Role of Ultrasonography Compared to Computed Tomography in Measurement of Visceral Adipose Tissue and Subcutaneous Adipose Tissue in Diabetic Overweight and Obese Adolescents

Background: Ultrasound is considered as a suitable, accurate, safe, available technique to measure abdominal adipose tissue of low cost compared to other imaging modalities as CT and MRI. It is superior to BMI as a monitor for diabesity because of it is ability to differentiate between visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in wide epidemiological studies. Results:  The correlation between the ultrasound and CT measurements was high with correlation coefficient 0.921 and 0.988 for VAT and SAT respectively. Also there was high significant correlation between the BMI and US and CT measurements of VAT and SAT in all studied groups with correlation coefficient ranging from 0.514 to 0.956. Conclusion: Ultrasound provides reproducible and valid estimates of VAT and SAT and represents a useful method to assess abdominal fat in large scale epidemiological studies.

Sex Differences of Visceral Fat Area and Visceral-to-Subcutaneous Fat Ratio for the Risk of Incident Type 2 Diabetes Mellitus

BACKGROUND

This study aimed to determine the optimal cut-off values of visceral fat area (VFA) and visceral-to-subcutaneous fat ratio (VSR) for predicting incident type 2 diabetes mellitus (T2DM).

METHODS

A total of 10,882 individuals (6,835 men; 4,047 women) free of T2DM at baseline aged between 30 and 79 years who underwent abdominal computed tomography scan between 2012 and 2013 as a part of routine health check-ups were included and followed. VFA, subcutaneous fat area, and VSR on L3 vertebral level were measured at baseline.

RESULTS

During a median follow-up of 4.8 years, 730 (8.1% for men; 4.3% for women) incident cases of T2DM were identified. Receiver operating characteristic curve analysis showed that the optimal cut-off values of VFA and VSR for predicting incident T2DM were 130.03 cm2 and 1.08 in men, respectively, and 85.7 cm2 and 0.48 in women, respectively. Regardless of sex, higher VFA and VSR were significantly associated with a higher risk of incident T2DM. Compared with the lowest quartiles of VFA and VSR, the highest quartiles had adjusted odds ratios of 2.62 (95% confidence interval [CI], 1.73 to 3.97) and 1.55 (95% CI, 1.14 to 2.11) in men, respectively, and 32.49 (95% CI, 7.42 to 142.02) and 11.07 (95% CI, 3.89 to 31.50) in women, respectively.

CONCLUSION

Higher VFA and VSR at baseline were independent risk factors for the development of T2DM. Sex-specific reference values for visceral fat obesity (VFA ≥130 cm2 or VSR ≥1.0 in men; VFA ≥85 cm2 or VSR ≥0.5 in women) are proposed for the prediction of incident T2DM.

Baseline associations between biomarkers, cognitive function, and self-regulation indices in the Cognitive and Self-regulatory Mechanisms of Obesity Study

OBJECTIVE

Understanding how biological, cognitive, and self-regulatory factors are related to obesity, and weight regulation is clearly needed to optimize obesity prevention and treatment. The objective of this investigation was to understand how baseline biological, cognitive, and self-regulatory factors are related to adiposity at the initiation of a behavioral weight loss intervention among treatment-seeking adults with overweight/obesity.

METHODS

Participants (N = 107) in the Cognitive and Self-regulatory Mechanisms of Obesity Study (Identifier-NCT02786238) completed a baseline assessment with anthropometric, cardiometabolic, inflammatory, cognitive function, and self-regulation measures as part of a larger on-going trial. Data were analyzed with linear regression.

RESULTS

At baseline, body mass index, body fat percentage, and waist circumference (WC) were positively associated with fasting insulin and insulin resistance. Higher WC was related to higher fasting glucose and hemoglobin A1c (HbA1c). Higher glucose and insulin resistance levels were related to lower list sorting working memory. Higher glucose and HbA1c levels were negatively associated with reading scores. Cognitive function and self-regulation indices were unrelated.

CONCLUSIONS

In adults with overweight/obesity entering a weight loss treatment study: (1) elevated WC and associated glycemic impairment were negatively associated with cognition, (2) poorer executive function and reading abilities were associated with poorer glycemic control, and (3) objectively measured cognitive functions were unrelated to self-reported/behavioral measures of self-regulation. Such findings increase understanding of the relationships between adiposity, biomarkers, cognition, and self-regulation at treatment initiation and may ultimately inform barriers to successful obesity treatment response.

The Acute Relationship between Affective States and Stress Biomarkers in Ethnic Minority Youths

Background: Whether affective states acutely predict the hypothalamic–pituitary–adrenal (HPA) axis activities and whether energy balance-related behaviors moderate the affect–HPA axis relationship in obese youths are not well-understood. Methods: 87 mostly obese (94.3% obese) minority adolescents (mean: 16.3 ± 1.2 years old; 56.8% Latino and 43.2% African American) participated in a randomized crossover trial in an observation laboratory, where they received either high-sugar/low-fiber (HSLF) or low-sugar/high-fiber (LSHF) meals first and then crossed over in the next visit 2–4 weeks later. During each visit, they rated five affective states and provided a saliva sample every 30 min for the first 5 h and wore a waist-worn accelerometer. The association between the affect ratings and cortisol levels in the subsequent 30 min and the moderation effect of energy balance-related behavior were examined using multilevel models. Results: Within-person negative affect (β = 0.02, p = 0.0343) and feeling of panic (β = 0.007, p = 0.004) were acutely related to the subsequent cortisol level only during the HSLF condition. The time spent in moderate-to-vigorous physical activity did not moderate the acute relationship between affect and the subsequent cortisol level. Conclusions: Negative affect could be acutely related to heightened HPA axis activities in youths, but only when they were exposed to meals with high sugar and low fiber content. These results suggest that the meals’ sugar and fiber content may modulate HPA axis reactivity to negative affect in youths.

Performance of Risk Assessment Models for Prevalent or Undiagnosed Type 2 Diabetes Mellitus in a Multi-Ethnic Population-The Helius Study

Background:

Most risk assessment models for type 2 diabetes (T2DM) have been developed in Caucasians and Asians; little is known about their performance in other ethnic groups.

Objective(s):

We aimed to identify existing models for the risk of prevalent or undiagnosed T2DM and externally validate them in a multi-ethnic population currently living in the Netherlands.

Methods:

A literature search to identify risk assessment models for prevalent or undiagnosed T2DM was performed in PubMed until December 2017. We validated these models in 4,547 Dutch, 3,035 South Asian Surinamese, 4,119 African Surinamese, 2,326 Ghanaian, 3,598 Turkish, and 3,894 Moroccan origin participants from the HELIUS (Healthy LIfe in an Urban Setting) cohort study performed in Amsterdam. Model performance was assessed in terms of discrimination (C-statistic) and calibration (Hosmer-Lemeshow test). We identified 25 studies containing 29 models for prevalent or undiagnosed T2DM. C-statistics varied between 0.77–0.92 in Dutch, 0.66–0.83 in South Asian Surinamese, 0.70–0.82 in African Surinamese, 0.61–0.81 in Ghanaian, 0.69–0.86 in Turkish, and 0.69–0.87 in the Moroccan populations. The C-statistics were generally lower among the South Asian Surinamese, African Surinamese, and Ghanaian populations and highest among the Dutch. Calibration was poor (Hosmer-Lemeshow p < 0.05) for all models except one.

Conclusions:

Generally, risk models for prevalent or undiagnosed T2DM show moderate to good discriminatory ability in different ethnic populations living in the Netherlands, but poor calibration. Therefore, these models should be recalibrated before use in clinical practice and should be adapted to the situation of the population they are intended to be used in.

Trajectories of Body Weight and Fat Mass in Relation to Incident Prediabetes in a Biracial Cohort of Free-Living Adults

Objectives

Obesity is a risk factor for type 2 diabetes (T2D), but prospective data relating adiposity measures to incident prediabetes are scant.

Methods

The Pathobiology of Prediabetes in A Biracial Cohort study followed normoglycemic African Americans (AA) and European Americans (EA) with parental history of T2D for the primary outcome of incident prediabetes (impaired fasting glucose and/or impaired glucose tolerance) for 5.5 years. Serial assessments included anthropometry and body fat composition. We analyzed weight, body mass index (BMI), waist, total, and abdominal fat mass in relation to incident prediabetes risk.

Results

Of the 376 subjects enrolled (217 AA, 159 EA; mean age 44.2 years, BMI 31.4 kg/m²), 343 (192 AA, 151 EA) had evaluable follow-up data. A total of 101 (52 AA, 49 EA) developed prediabetes during follow-up. Progressors to prediabetes had a mean baseline weight of 90.0 ± 20.4 kg versus 82.9 ± 21.7 kg among nonprogressors (P = 0.0036). During 5.5 (mean 2.62) years of follow-up, the weight change among nonprogressors was 0.63 ± 6.11 kg compared with 2.54 ± 6.91 kg among progressors (ANOVA P = 0.0072). Progressors also showed greater increases in total fat (P = 0.0015) and trunk fat (P = 0.0005) mass than nonprogressors. Adjusted for age and sex, the significant predictors of incident prediabetes were BMI (P = 0.0013), waist (P < 0.0001), total fat (P = 0.0025), and trunk fat (P < 0.0001) mass.

Conclusions

Among obese free-living offspring of parents with T2D, long-term normoglycemic status was associated with a weight gain of ~0.2 kg/y, whereas progression to prediabetes was associated with a weight gain of ~1 kg/y.

Review of methods for detecting glycemic disorders

Prediabetes (intermediate hyperglycemia) consists of two abnormalities, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) detected by a standardized 75-gram oral glucose tolerance test (OGTT). Individuals with isolated IGT or combined IFG and IGT have increased risk for developing type 2 diabetes (T2D) and cardiovascular disease (CVD). Diagnosing prediabetes early and accurately is critical in order to refer high-risk individuals for intensive lifestyle modification. However, there is currently no international consensus for diagnosing prediabetes with HbA1c or glucose measurements based upon American Diabetes Association (ADA) and the World Health Organization (WHO) criteria that identify different populations at risk for progressing to diabetes. Various caveats affecting the accuracy of interpreting the HbA1c including genetics complicate this further. This review describes established methods for detecting glucose disorders based upon glucose and HbA1c parameters as well as novel approaches including the 1-hour plasma glucose (1-h PG), glucose challenge test (GCT), shape of the glucose curve, genetics, continuous glucose monitoring (CGM), measures of insulin secretion and sensitivity, metabolomics, and ancillary tools such as fructosamine, glycated albumin (GA), 1,5- anhydroglucitol (1,5-AG). Of the approaches considered, the 1-h PG has considerable potential as a biomarker for detecting glucose disorders if confirmed by additional data including health economic analysis. Whether the 1-h OGTT is superior to genetics and omics in providing greater precision for individualized treatment requires further investigation. These methods will need to demonstrate substantially superiority to simpler tools for detecting glucose disorders to justify their cost and complexity.

General and Central Adiposity in Older Adults in Palmas (TO): Prevalence and Associated Factors

Objectives: To evaluate the prevalence and associated factors with general and central adiposity in older adults in Palmas (TO).Methods: Cross-sectional study with older adults (≥60 years) of both sexes enrolled in the Family Health Strategy program in Palmas (TO). Sociodemographic aspects, health conditions, and functionality were evaluated as independent variables and Body Mass Index (BMI) for general adiposity and Waist Circumference (WC) for central adiposity as dependent variables. Descriptive analysis and hierarchical multiple Poisson regression with robust variance were performed.Results: A total of 449 seniors (50.6% women) from 60 to 92 years of age, average of 68.3 years, were evaluated. The prevalence of general adiposity was 46.8% (95% CI: 42.2%-51.4%) and central adiposity was 78.8% (95% CI: 74.7%-82.3%). The prevalence of both outcomes was significantly higher among women and the participants with a history of hypertension, diabetes, dyslipidemia, and rheumatic diseases and those dependent in activities of daily living (ADL) than among men. Lower frequency of adiposity (general and central) was found with increasing age. After adjustment, the prevalence of both outcomes was significantly higher in women aged 70-79 years and hypertensive.Conclusions: The results of this study confirm the need to establish nutritional status monitoring and direct obesity prevention and control interventions in programs to promote health and quality of life of older adults and those in the stages prior to old age.

The Separate Contributions of Visceral Fat and Liver Fat to Chronic Kidney Disease-Related Renal Outcomes

OBJECTIVES

This study aims to investigate the separate contributions of liver fat and visceral fat on microalbuminuria and impaired renal function, and second, to examine whether non-alcoholic fatty liver disease is causally related to microalbuminuria and/or impaired renal function.

METHODS

Associations between visceral adipose tissue (VAT), hepatic triglyceride content (HTGC), and risk of microalbuminuria and renal function were studied cross-sectionally in the Netherlands Epidemiology of Obesity study. Mendelian randomization using GWAS meta-analysis data was performed to estimate the causal effect of non-alcoholic fatty liver disease (PNPLA3, LYPLAL1, NCAN, GCKR) on eGFR (N_max 118,460), microalbuminuria (N_max 54,116), and impaired renal function (N_max 118,147).

RESULTS

In total, 2,023 participants (mean age 55.5 ± 6.0 years, 53% women) were included of which 29% had fatty liver and 2.0% chronic kidney disease stage ≥3. In joint models, VAT was associated with a 2-fold increased risk of microalbuminuria which was mainly driven by the association in women (total population: per standard deviation [SD] = 55.4 cm², odds ratio [OR] 2.02, 95% confidence interval [CI] 1.18-3.47; women: OR 2.83, 95% CI 1.44, 5.56), but HTGC was not (total population: per SD = 7.9%, OR 1.20, 95% CI 0.85, 1.70). No associations were found for VAT and HTGC with eGFR (VAT: per SD = 55.4 cm², OR 1.25, 95% CI 0.83, 1.87; HTGC: per SD = 7.9%, OR 0.65, 95% CI 0.42, 0.99). No causal effect of NAFLD on microalbuminuria or impaired renal function was found.

CONCLUSIONS

In observational analyses, visceral fat was associated with microalbuminuria in women. Liver fat was not associated with microalbuminuria or renal function, which was supported by Mendelian randomization. Visceral fat might be more important than liver fat in the etiology of microalbuminuria.

Clinical and genetic differences between heterozygous familial hypercholesterolemia patients with and without type 2 diabetes

INTRODUCTION AND OBJECTIVES

The lower prevalence of type 2 diabetes mellitus (T2DM) in patients with heterozygous familial hypercholesterolemia (HeFH) could explain why T2DM has not always been identified as an independent predictor of cardiovascular disease (CVD) in different familial hypercholesterolemia cohort studies. The aim of the present study was to evaluate clinical and genetic aspects of HeFH patients with T2DM in the dyslipidemia registry of the Spanish Arteriosclerosis Society.

METHODS

HeFH patients were classified according to the presence or absence of T2DM. The clinical, biochemical and genetic characteristics of the 2 groups were compared.

RESULTS

Of the 2301 patients with primary hypercholesterolemia included in the registry, 1724 with a probable or definite diagnosis according to the Dutch Lipid Clinic Network score were finally included. HeFH patients with T2DM had a higher rate of CVD and a less favorable lipid profile, with higher total cholesterol (366.9±86.7mg/dL vs 342.0±74.7mg/dL; mean difference 24.894; 95%CI, 5.840-43.949) and non-high-density lipoprotein cholesterol (316.9±87.8mg/dL vs 286.4±75.4mg/dL; mean difference 30.500; 95%CI, 11.211-49.790) levels. No significant differences were found between the groups concerning the specific type of HeFH-causing mutation (P=.720). After adjustment for major risk factors, logistic regression analysis confirmed a relationship between T2DM and the presence of CVD (OR, 2.01; 95%CI, 1.18-3.43; P=.010).

CONCLUSIONS

HeFH patients with T2DM have a higher rate of CVD and a less favorable lipid profile, regardless of genetic mutation type. In these patients, T2DM is associated with the presence of CVD.

Anthropometric changes and risk of diabetes: are there sex differences? A longitudinal study of Alberta's Tomorrow Project

OBJECTIVES

To characterise the sex-specific difference in the association between anthropometric changes and risk of diabetes in the general population in Canada.

SETTING AND PARTICIPANTS

From 2000 to 2008, Alberta's Tomorrow Project (ATP) invited Alberta's residents aged 35-69 years to a prospective cohort study. A total of 19 655 diabetes-free ATP participants having anthropometrics measured at the baseline and follow-ups were included.

DESIGN AND OUTCOME MEASURES

A longitudinal study design was used to examine the association between anthropometric changes and risk of diabetes and the sex difference in this association. Changes in weight, body mass index (BMI), waist circumference (WC) and waist-hip-ratio (WHR) were calculated as the difference between baseline and follow-up measures. Diabetes cases were identified using the Canadian National Diabetes Surveillance System algorithm with administrative healthcare data (2000-2015) linked to the ATP cohort. The sex-specific association between anthropometric changes and incidence of diabetes were examined by multivariable Cox regression models.

RESULTS

Changes in weight, BMI, WC and WHR over time were positively associated with incidence of diabetes in both men and women. The sex difference in risk of diabetes associated with 1 standard deviation (SD) increase in anthropometrics was 0.07 (95% CI -0.02 to 0.14) for weight, 0.08 (95% CI -0.03 to 0.17) for BMI, 0.07 (95% CI -0.02 to 0.15) for WC and 0.09 (95% CI 0.03 to 0.13) for WHR. Similar results were found in sex difference in the associations with changes per 5% and changes per categories (5% loss, ±5%, 5% gain).

CONCLUSIONS

The positive association between anthropometric changes and risk of diabetes was generally stronger in men than in women. However, this sex-specific difference of approximately 10% of the total risk associated with anthropometric changes had limited significance. For population-based public health programmes aiming to control obesity and incidence of diabetes, it may not be necessary to set up sex-specific goals for anthropometric reduction.

Clinical and genetic characteristics of familial hypercholesterolemia patients with type 2 diabetes

PURPOSE

Though type 2 diabetes mellitus (T2DM) is an important and independent risk factor for coronary artery disease (CAD) in the general population, the impact of T2DM on CAD in patients with familial hypercholesterolemia (FH) is less understood. Thus, the current study aimed to examine the features of FH patients with T2DM and explore the effects of T2DM on CAD in FH.

METHODS

A total of 289 clinical heterozygous FH (HeFH) patients diagnosed with Dutch Lipid Clinic Criteria were consecutively recruited and divided into a T2DM group (n = 58) and non-T2DM group (n = 231). Clinical characteristics and laboratory findings were compared between the two groups. Target exome sequencing was used for gene mutation analysis.

RESULTS

HeFH patients with T2DM had significantly higher levels of triglycerides, body mass index and free fatty acids than did non-T2DM patients; moreover, patients with T2DM more frequently exhibited hypertension. However, the spectrum of FH-causing mutations was not significantly different (p = 0.061). Notably, patients with T2DM had higher prevalence of CAD (p = 0.012) and higher Gensini Score (p = 0.002). The regression analysis confirmed that HbA1c was an independent risk factor for both the presence and severity of CAD [OR 2.321 (1.098-4.904), p = 0.027; OR 1.349 (1.032-1.762), p = 0.028, respectively] in patients with HeFH.

CONCLUSIONS

Although there were not many differences in the clinical, lipid and genetic aspects of HeFH patients with and without T2DM, T2DM and HbA1c were associated with worse coronary lesions, suggesting that diabetes and the degree of blood glucose control are also important determinants of cardiovascular disease in these patients.

The triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio as a predictor of insulin resistance, β-cell function, and diabetes in Hispanics and African Americans

OBJECTIVE

The TG/HDL-C ratio is used as a marker of insulin resistance (IR) in Caucasians; however, there is limited data in other ethnic groups. We hypothesized that the TG/HDL-C ratio is associated with IR in Hispanics and African Americans (AA).

RESEARCH DESIGN AND METHODS

Data from the Insulin Resistance Atherosclerosis Family Study was examined for associations between TG/HDL-C ratio and IR, β-cell function and incident diabetes in non-diabetic Hispanics (n = 872, 63% female) and AA (n = 371, 61% female). Insulin sensitivity index (S_I) and disposition index (DI) from frequently-sampled intravenous glucose tolerance tests were used as markers of IR and β-cell function respectively. Incident type 2 diabetes was determined by fasting glucose ≥ 126 mg/dl or initiation of anti-hyperglycemia agents over 5 year follow-up.

RESULTS

Higher TG/HDL-C ratio was associated with IR in Hispanic and AA men and women (P < 0.0002), as well as β-cell function in Hispanic women and AA men and women (P < 0.02). TG/HDL-C predicted incident type 2 diabetes in women (area under the curves 0.703 and 0.795 for Hispanics and AA respectively).

CONCLUSIONS

Similar to Caucasians, the TG/HDL-C ratio can be used to identify IR in Hispanics and AA, and may predict type 2 diabetes in women.

High waist-to-hip ratio levels are associated with insulin resistance markers in normal-weight women

AIM

To assess the association between high waist-to-hip ratio (WHR) levels and insulin resistance (IR) or hyperinsulinemia after oral glucose tolerance test (OGTT) in a sample of normal-weight women.

METHODS

We conducted an analytical cross-sectional study in euthyroid non-diabetic women, who attended the outpatient service of a private clinic in Lima-Peru from 2012 to 2016. Participants were divided in two groups according to the presence or absence of high WHR levels, IR or hyperinsulinemia after OGTT. We considered WHR values > 0.85 as high levels. IR was defined as a Homeostasis Model Assessment (HOMA-IR) value > 2.39 and hyperinsulinemia after OGTT as a serum insulin value ≥ 80μU/mL after 120 min of 75-g glucose intake. We elaborated crude and adjusted Poisson generalized linear models to evaluate the association between high WHR levels and IR or hyperinsulinemia after OGTT and reported the prevalence ratio (PR) with their respective 95% confidence intervals (95%CI).

RESULTS

We analyzed the data of 248 euthyroid, non-diabetic and normal-weight women. The prevalence of high WHR levels was 68.9% (n = 171) while the prevalence of IR and hyperinsulinemia after OGTT was 25% (n = 62) and 15.3% (n = 38), respectively. WHR values were positively correlated with HOMA-IR (r = 0.307; p < 0.001) and serum insulin after OGTT (r = 0.260; p < 0.001). In the adjusted model, high WHR levels were associated with both IR (aPR = 2.63; 95%CI: 1.39-5.01) and hyperinsulinemia after OGTT (aPR = 2.35; 95%CI: 1.03-5.38).

CONCLUSION

High WHR levels were associated with both IR markers used in our study, appearing to be a useful anthropometric indicator to assess IR in euthyroid normal-weight women without type 2 diabetes mellitus.

DEXAMETHASONE STRESS TEST: A PILOT CLINICAL STUDY FOR IDENTIFICATION OF INDIVIDUALS HIGHLY PRONE TO DEVELOP TYPE 2 DIABETES

OBJECTIVE

We examined whether the "Dexamethasone Stress Test" exhibits the requisite high predictive ability to identify individuals highly prone to develop type 2 diabetes mellitus (T2DM).

METHODS

Seven years ago, we administered an oral glucose tolerance test (OGTT) to 33 individuals without T2DM and repeated the OGTT 24 hours after a single oral dose of 8 mg dexamethasone (Dex); all participants had a first-degree relative with T2DM, and close to half had prediabetes. We calculated receiver operating characteristic (ROC) curves for all parameters derived from the OGTT before and after Dex in individuals who subsequently developed diabetes compared to individuals who did not.

RESULTS

At 7 years of follow-up, 9 individuals had developed T2DM, while 24 remained without diabetes. None of the OGTT-derived parameters before administration of Dex had an area under the ROC curve of >0.8. However, 24 hours after Dex, three parameters, including fasting plasma insulin, homeostatic model assessment-insulin resistance, and 2-hour plasma glucose level, exhibited areas under the ROC curves of 0.84, 0.86, and 0.92, respectively.

CONCLUSION

The Dexamethasone Stress Test appears to be a good to excellent test in identifying individuals highly prone to develop T2DM.

ABBREVIATIONS

AUC = area under the curve; Dex = dexamethasone; HOMA-IR = homeostatic model assessment-insulin resistance; NGT = normal glucose tolerance; OGTT = oral glucose tolerance test; PreDiab = prediabetes; ROC = receiver operating characteristic; T2DM = type 2 diabetes mellitus.

Prenatal famine exposure, adulthood obesity patterns and risk of type 2 diabetes

Background

Prenatal exposure to famine and adulthood obesity have been independently related to the risk of type 2 diabetes; however, little is known about the joint effects of these risk factors at different stages of life on adulthood diabetes risk.

Methods

The analysis included 88 830 participants of the China Kadoorie Biobank, who were born around the time of the Chinese Great Famine and without diabetes, cardiovascular diseases, or cancer at baseline. We defined famine exposure subgroups as nonexposed (born between 1 October 1962 and 30 September 964), fetal-exposed (born between 1 October 1959 and 30 September 1961) and early-childhood exposed (born between 1 October 1956 and 30 September 1958). General obesity was assessed by body mass index (BMI: overweight ≥ 24.0, obesity ≥ 28.0) and abdominal obesity assessed by waist-to-hip ratio (WHR, men/women: moderate ≥ 0.90/0.85, high ≥ 0.95/0.90).

Results

During a median 7.3 years (642 552 person-years) of follow-up, we identified 1372 incident cases of type 2 diabetes. Compared with nonexposed and early-childhood exposed participants combined as a single comparison group, fetal-exposed participants showed an increased risk of diabetes in adulthood [hazard ratio (HR) = 1.25; 95% confidence interval (CI): 1.07-1.45]. The association between general obesity and diabetes was consistent across subgroups according to famine exposure (P for interaction > 0.05). A stronger association between abdominal obesity and diabetes was observed in the fetal-exposed subgroup than in other subgroups (P for interaction = 0.025 in the whole population). This interaction was more obvious in women (P = 0.013) but not in men (P = 0.699). Compared with normal-BMI and -WHR participants, those with both general (BMI ≥ 24.0) and abdominal (WHR ≥ 0.90/0.85) obesity in adulthood had 5.32 (95% CI: 3.81-7.43)-, 3.13 (2.48-3.94)- and 4.43 (3.45-5.68)-fold higher risks if these were carried during, before and after times of famine, respectively.

Conclusions

Coexistence of prenatal experience of undernutrition and abdominal obesity in adulthood was associated with a higher risk of type 2 diabetes.

Insulin resistance increases the risk of incident type 2 diabetes mellitus in patients with non-alcoholic fatty liver disease

AIM

Type 2 diabetes mellitus (T2DM) is a major complication of patients with non-alcoholic fatty liver disease (NAFLD). The aim of this retrospective study is to determine the risk factors for development of T2DM in patients with biopsy-proven NAFLD.

METHODS

One hundred and sixty two consecutive patients with biopsy-proven NAFLD who received a 75-g oral glucose tolerance test were enrolled as the total cohort. Among them, we analyzed 89 patients without T2DM diagnosed by oral glucose tolerance test to estimate the cumulative rate for development of T2DM as the follow-up cohort.

RESULTS

Of 162 patients, the glucose tolerance pattern were DM in 45 patients (27.8%), impaired glucose tolerance in 68 (42.0%), and normal glucose tolerance in 49 (30.2%). Patients with NAFL tended to be more likely to have normal glucose tolerance than those with non-alcoholic steatohepatitis (NASH). The serum levels of pre- and post-load insulin were significantly higher in the NASH group. Of 89 patients without T2DM, 13 patients newly developed T2DM during a follow-up period of 5.2 years. The cumulative rate of T2DM incidence was 8.8% at the end of the 5th year and 23.4% at the end of the 10th year. Multivariate analysis identified homeostasis model of assessment - insulin resistance (≥3.85, hazard ratio 40.1, P = 0.033) as an independent risk factor for development of T2DM.

CONCLUSIONS

Patients with NASH have an underlying potential of glucose intolerance. In NAFLD patients, insulin resistance is the most important risk factor for the incidence of T2DM. Appropriate therapy against insulin resistance could be needed for patients with NAFLD to prevent development of T2DM.

Associations of Abdominal Subcutaneous and Visceral Fat with Insulin Resistance and Secretion Differ Between Men and Women: The Netherlands Epidemiology of Obesity Study

BACKGROUND

Abdominal obesity is a well-established risk factor for the development of type 2 diabetes. However, sex differences may exist. We aimed to investigate the associations of abdominal subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) with insulin resistance and insulin secretion in men and women.

METHODS

In this cross-sectional analysis of the Netherlands Epidemiology of Obesity study, fasting and postprandial concentrations of glucose and insulin were measured and abdominal fat depots were assessed using magnetic resonance imaging in 2253 participants (53% women). With linear regression analysis, we examined associations of abdominal SAT and VAT with measures of insulin resistance and insulin secretion in men and women, while adjusting for age, ethnicity, education, smoking habits, alcohol consumption, menopausal state and hormone use in women, and models with VAT additionally for total body fat.

RESULTS

Participants had a mean [standard deviation (SD)] age of 56 (6) years, body mass index: 25.9 (3.9) kg/m², VAT: 89 (55) cm², and SAT: 235 (95) cm². In the multivariate models in men, per SD of VAT the homeostatic model assessment of insulin resistance (HOMA-IR) was 20% (95% CI: 14-26) higher, and per SD SAT 21% (15-27) higher. In women, per SD of VAT the HOMA-IR was 40% (29-52) higher, and per SD SAT 12% (6-19) higher. Associations with measures of insulin secretion were weaker than with insulin resistance.

CONCLUSIONS

In men, abdominal SAT and VAT were associated with insulin resistance to a similar extent, whereas in women particularly VAT was associated with insulin resistance and insulin secretion. Future studies need to unravel the mechanisms underlying the metabolic effects of visceral fat in women. Simple and less expensive measures that can distinct abdominal subcutaneous and visceral fat are needed for an improved metabolic risk stratification.

Lack of efficacy of pomegranate supplementation for glucose management, insulin levels and sensitivity: evidence from a systematic review and meta-analysis

Background

The potential glucose-lowering effects of pomegranate have been reported in animal and observational studies, but intervention studies in humans have generated mixed results. In this paper, we aimed to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the precise effects of pomegranate supplementation on measures of glucose control, insulin levels and insulin sensitivity in humans.

Methods

Comprehensive electronic searches were conducted in PubMed, Embase, and the Cochrane Library. Studies included were RCTs that evaluated the changes in diabetes biomarkers among adults (≥18 years) following pomegranate interventions. The predefined outcomes included fasting blood glucose (FBG), fasting blood insulin (FBI), glycated haemoglobin (HbA1c), and homeostatic model assessment of insulin resistance (HOMA-IR). Endpoints were calculated as weighted mean differences (WMDs) with 95% confidence intervals (CIs) by using a random-effects model. Publication bias, subgroup analyses, sensitivity analysis and random-effects meta-regression were also performed to explore the influence of covariates on the net changes in fasting glucose and insulin concentrations.

Results

Sixteen eligible trials with 538 subjects were included. The pooled estimates suggested that pomegranate did not significantly affect the measures of FBG (WMD, −0.6 mg/dL; 95% CI, −2.79 to 1.58; P=0.59), FBI (WMD, 0.29 μIU/mL; 95% CI, −1.16 to 1.75; P=0.70), HOMA-IR (WMD, −0.04; 95% CI, −0.53 to 0.46; P=0.88) or HbA1c (WMD, −0.11%; 95% CI, −0.39 to −0.18; P=0.46). Overall, significant heterogeneity was detected for FBI and HOMA-IR, but subgroup analysis could not identify factors significantly influencing these parameters. These results were robust in sensitivity analysis, and no significant publication bias was found in the current meta-analysis.

Conclusion

Pomegranate intake did not show a notably favourable effect on improvements in glucose and insulin metabolism. The current evidence suggests that daily pomegranate supplementation is not recommended as a potential therapeutic strategy in glycemic management. Further large-scale RCTs with longer duration are required to confirm these results.

Electronic supplementary material

The online version of this article (10.1186/s12937-017-0290-1) contains supplementary material, which is available to authorized users.

Association of Directly Measured Plasma Free 25(OH)D With Insulin Sensitivity and Secretion: The IRAS Family Study

Objectives

We aimed to compare the associations of directly measured plasma free 25-hydroxyvitamin D [25(OH)D] and total 25(OH)D concentrations with insulin sensitivity (SI) and β-cell function in nondiabetic Hispanics and African Americans. We hypothesized that directly measured free 25(OH)D would be more strongly associated with these measures of glucose homeostasis and that associations would differ by race.

Design

We studied 1189 nondiabetic participants in the Insulin Resistance Atherosclerosis Study Family Study using data from baseline examinations from 2000 to 2002. SI, acute insulin response, and disposition index (DI) were determined from frequently sampled intravenous glucose tolerance tests. Plasma free and total 25(OH)D concentrations were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively.

Results

The median concentrations of plasma free 25(OH)D were 3.46 pg/mL for Hispanics and 2.17 pg/mL for African Americans (P < 0.0001), whereas the median concentrations of plasma total 25(OH)D were 16 ng/mL for Hispanics and 10 ng/mL for African Americans (P < 0.0001). Plasma free and total 25(OH)D were both positively associated with SI and DI in generalized estimating equations adjusted for demographic and lifestyle factors. After further adjustment with body mass index, the associations were no longer statistically significant, except for a significant association between plasma free 25(OH)D and SI. There was no effect modification by ethnicity on any of the exposure-outcome associations.

Conclusions

Our data showed that plasma free 25(OH)D had a slightly stronger association with SI compared with plasma total 25(OH)D, although the difference was modest and there were no marked differences in the associations between Hispanics and African Americans.

ASSOCIATION OF PANCREAS VOLUME AND INSULIN RESISTANCE WITH ABDOMINAL FAT DISTRIBUTION IN TYPE-2 DIABETES AS EVALUATED BY COMPUTED TOMOGRAPHY

PURPOSE

We aimed to assess the relationship between the regional body fat distribution and insulin resistance and pancreas volume (PV) in type-2 diabetes (DM) patients.

METHODS

Fifty-three consecutive type-2 diabetic and 51 non-diabetic patients matched by age, gender and body mass index (BMI) were enrolled. Subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), waist circumference, and PV were measured with computed tomography. Insulin resistance was assessed by the homeostasis model assessment of insulin resistance (HOMA-IR).

RESULTS

Patients with type-2 DM had significantly lower PV than non-diabetic individuals. HOMA-IR ranged from 0.74 to 6.24; and from 0.37 to 3.26, in type-2 DM patients and non-diabetics, respectively. VAT was positively correlated with HOMA-IR in two groups. There were inverse correlations between PV and VAT and VAT/SAT but only in diabetics.

CONCLUSIONS

The VAT/SAT ratio may reflect the possible role of VAT to better understand the pathogenesis of obesity-related disorders in patients with type-2 DM.

Body mass index adjustments to increase the validity of body fatness assessment in UK Black African and South Asian children

Background/Objectives:

Body mass index (BMI) (weight per height²) is the most widely used marker of childhood obesity and total body fatness (BF). However, its validity is limited, especially in children of South Asian and Black African origins. We aimed to quantify BMI adjustments needed for UK children of Black African and South Asian origins so that adjusted BMI related to BF in the same way as for White European children.

Methods:

We used data from four recent UK studies that made deuterium dilution BF measurements in UK children of White European, South Asian and Black African origins. A height-standardized fat mass index (FMI) was derived to represent BF. Linear regression models were then fitted, separately for boys and girls, to quantify ethnic differences in BMI–FMI relationships and to provide ethnic-specific BMI adjustments.

Results:

We restricted analyses to 4–12 year olds, to whom a single consistent FMI (fat mass per height⁵) could be applied. BMI consistently underestimated BF in South Asians, requiring positive BMI adjustments of +1.12 kg m⁻² (95% confidence interval (CI): 0.83, 1.41 kg m⁻²; P<0.0001) for boys and +1.07 kg m⁻² (95% CI: 0.74, 1.39 kg m⁻²; P<0.0001) for girls of all age groups and FMI levels. BMI overestimated BF in Black Africans, requiring negative BMI adjustments for Black African children. However, these were complex because there were statistically significant interactions between Black African ethnicity and FMI (P=0.004 boys; P=0.003 girls) and also between FMI and age group (P<0.0001 for boys and girls). BMI adjustments therefore varied by age group and FMI level (and indirectly BMI); the largest adjustments were in younger children with higher unadjusted BMI and the smallest in older children with lower unadjusted BMI.

Conclusions:

BMI underestimated BF in South Asians and overestimated BF in Black Africans. Ethnic-specific adjustments, increasing BMI in South Asians and reducing BMI in Black Africans, can improve the accuracy of BF assessment in these children.

Higher Ratio of Abdominal Subcutaneous to Visceral Adipose Tissue Related with Preservation of Islet β-Cell Function in Healthy Individuals

OBJECTIVE

To investigate the relationship between abdominal adipose tissue distribution, β-cell function, and insulin sensitivity (IS) in a Chinese population.

METHODS

One hundred and eighty-eight healthy subjects (healthy group), 239 with normal glucose, and 1~4 abnormal metabolic traits (metabolic dysfunction group, MD group) and 125 with hyperglycemia (hyperglycemia group) were studied. HOMA-IR, HOMA-B, Matsuda index, early- (I_0-30/G_0-30) and late-phase (I_30-120/G_30-120) insulin responses and the corresponding disposition indexes (DI) were calculated. The area of abdominal subcutaneous adipose tissue (ASAT) and visceral adipose tissue (VAT) was measured and the ratio of ASAT to VAT (SVR) was calculated.

RESULTS

SVR was correlated positively with Matsuda index in healthy, MD, and hyperglycemia groups, and inversely with HOMA-IR. SVR positively related with both early- and late-phase DI in the healthy group only. In the healthy group, the hyperbolas of I_0-30/G_0-30 and I_30-120/G_30-120 versus Matsuda index in the highest quarter of SVR were significantly right shifted compared to those in the lowest (both P < 0.05).

CONCLUSIONS

In healthy adults, higher SVR was a protective factor for β-cell function and IS, while in those with glucometabolic abnormality, higher SVR contributed to a relative better IS, indicating SVR is possible to be an early predicator of type 2 diabetes development.

Sweetened beverage intake and risk of latent autoimmune diabetes in adults (LADA) and type 2 diabetes

OBJECTIVE

Sweetened beverage intake is associated with increased risk of type 2 diabetes, but its association with autoimmune diabetes is unclear. We aimed to investigate sweetened beverage intake and risk of latent autoimmune diabetes in adults (LADA); autoimmune diabetes with features of type 2 diabetes.

DESIGN/METHODS

Data from a Swedish population-based study was used, including incident cases of LADA (n = 357) and type 2 diabetes (n = 1136) and randomly selected controls (n = 1371). Diabetes classification was based on onset age (≥35), glutamic acid decarboxylase autoantibodies (GADA) and C-peptide. Sweetened beverage intake information was derived from a validated food frequency questionnaire. ORs adjusted for age, sex, family history of diabetes, education, lifestyle, diet, energy intake and BMI were estimated using logistic regression.

RESULTS

Daily intake of >2 servings of sweetened beverages (consumed by 6% of participants) was associated with increased risk of LADA (OR: 1.99, 95% CI: 1.11-3.56), and for each 200 mL daily serving, OR was 1.15 (95% CI: 1.02-1.29). Findings were similar for sugar-sweetened (OR: 1.18, 95% CI: 1.00-1.39) and artificially sweetened beverages (OR: 1.12, 95% CI: 0.95-1.32). Similarly, each daily serving increment in total sweetened beverage conferred 20% higher type 2 diabetes risk (95% CI: 1.07-1.34). In type 2 diabetes patients, high consumers displayed higher HOMA-IR levels (4.5 vs 3.5, P = 0.0002), but lower HOMA-B levels (55 vs 70, P = 0.0378) than non-consumers. Similar tendencies were seen in LADA.

CONCLUSIONS

High intake of sweetened beverages was associated with increased risk of LADA. The observed relationship resembled that with type 2 diabetes, suggesting common pathways possibly involving insulin resistance.

Association between race, obesity and diabetes in elderly community dwellers: data from the FIBRA study

This study sought to investigate the effect of race on measures of body fat (body mass index - BMI, waist circumference - WC and waist-hip ratio - WHR), as well as its relationship with diabetes, among elderly individuals living in urban areas in seven places in Brazil, according to gender. This is a cross-sectional study carried out with a probabilistic sample comprising 2,566 individuals with 65 years of age or more who participated in the FIBRA Study (Frailty in Elderly Brazilians). We used several self-reported sociodemographic variables (gender, age, race, schooling and family income), anthropometric measures of general (BMI) and abdominal obesity (WC and WHR) and self-reported diabetes. Adjusting for schooling and income, white race was associated with higher WC values (p = 0.001) and WHR (p > 0.001) for male gender, regardless of diabetes status. However, when we considered only diabetic individuals, black race became associated with general (BMI) (p = 0.007) and central obesity (CC) (p > 0.001), only among women.

Chronic sub-clinical inflammation in the abdominal adipose tissue - Evaluation of inflammatory cytokines and their link with insulin resistance in metabolically obese South Indians: A cross-sectional observational study

OBJECTIVE

To measure the levels of proinflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-6(IL-6), and high-sensitive C-reactive protein (hs-CRP) and the anti-inflammatory cytokine adiponectin (AN) in obese South Indian subjects and to ascertain whether or not a causal role could be ascribed to these cytokines in the development of insulin resistance (IR).

MATERIALS AND METHODS

Forty obese and forty nonobese volunteers of both genders were recruited. Parameters such as body mass index (BMI), waist circumference (WC), and blood pressure were evaluated. Fasting blood sugar (FBS), fasting insulin level, hemoglobin A1c (HbA1C), lipid profile, TNF-α, IL-6, hs-CRP, and AN levels were measured. IR was evaluated by homeostatic model assessment-IR method. Abdominal adiposity was measured by ultrasonography. The results were statistically evaluated by appropriate tests.

RESULTS

BMI, WC, and visceral fat were high in the obese group. Females had higher subcutaneous fat in both groups. HbA1C was marginally high in the obese group (P = 0.014). IR was high in all the groups, obese males showing higher values (not significant[NS]). Total cholesterol and low-density lipoprotein were high in the obese group (P = 0.028, P = 0.003). TNF-α was high in obese males (NS), IL-6 was high in both groups, higher in nonobese females (NS), hs-CRP was high in both groups, higher in females of both groups (NS). AN was high in females of both groups (P = 0.002).

CONCLUSIONS

In this study on South Indian subjects, proinflammatory cytokines such as IL-6 and hs-CRP, despite being high, did not show any causal correlation either with abdominal obesity or with IR. TNF-α being normal showed some correlation which was inconsistent. Even the anti-inflammatory adipokine, AN did not show any correlation with IR. Cytokines had an inconsistent correlation with the components of metabolic syndrome hence were not useful.

Comparison of Abdominal Visceral Adipose Tissue Area Measured by Computed Tomography with That Estimated by Bioelectrical Impedance Analysis Method in Korean Subjects

We evaluated the concordance between visceral fat area (VFA) estimated by bioelectrical impedance analysis (BIA) or computed tomography (CT) in Korean subjects with a wide range in age and body mass index (BMI). In 1006 individuals (mean age 55.2 ± 11.8 (19-87) years, mean BMI 26.0 ± 3.5 (17-46) kg/m², 48.9% men), VFA quantified by CT was compared with VFA using multifrequency BIA machines within 15 days. Concordance rates were compared by age or BMI using correlation analysis, Bland-Altman plots, and intraclass correlation coefficient (ICC). Using BIA data, we established a regression formula to reflect CT-VFA. The mean VFAs by CT and BIA were 131.9 ± 57.3 cm² and 110.5 ± 33.9 cm², respectively (r = 0.605, p < 0.001). The mean difference was 21.4 ± 45.6 cm², tending to increase with BMI. In women with BMI <25 kg/m² or age <50 years, the VFAs by BIA were similar to those by CT (ICC = 0.496 in BMI <25 kg/m² and ICC = 0.638 in age <50 years). However, the difference was greater in men with BMI ≥25 kg/m² or age ≥50 years. Applying our formula, the difference between estimations decreased to 0.2 ± 38.2cm². VFA estimated by BIA correlated well with that by CT, but a more accurate formula is needed to match CT data, particularly in older men or subjects with a high BMI.

Is Insulin Resistance a Feature of or a Primary Risk Factor for Cardiovascular Disease?

The two major pathophysiological abnormalities in type 2 diabetes are insulin resistance and impaired insulin secretion. Insulin resistance is a general term meaning that insulin does not exert its normal effects in insulin-sensitive target tissues, such as skeletal muscle, adipose tissue, and liver, the major target tissues for insulin action in glucose metabolism. Insulin resistance (IR) promotes cardiovascular disease via multiple mechanisms, including changes in classic cardiovascular risk factors and downregulation of the insulin signaling pathways in different tissues. This review presents evidence for the association of insulin resistance with cardiovascular disease from clinical and population-based studies. The causality of the association of insulin resistance with cardiovascular disease is discussed on the basis of recent findings from the Mendelian randomization studies.

Novel Risk Factors for Type 2 Diabetes in African-Americans

In the USA, compared to whites, African-Americans are disproportionately impacted by the diabetes epidemic. Traditional diabetes risk factors, such as obesity, are more common among African-Americans, but these traditional risk factors do not explain all of the disparity in diabetes risk. Recent research has identified novel environmental, lifestyle, physiologic, and genetic risk factors for diabetes, some of which appear to impact African-Americans more than whites. This manuscript reviews the recent literature to highlight some of these novel risk factors that may be contributing to the racial disparity in diabetes risk. Further study is needed of the modifiable risk factors for development of interventions to reduce the risk of diabetes in African-Americans, as well as other high-risk populations.

Cut-off points of homeostasis model assessment of insulin resistance, beta-cell function, and fasting serum insulin to identify future type 2 diabetes: Tehran Lipid and Glucose Study

AIMS

To determine cut-off points of homeostasis model assessment of insulin resistance (HOMA-IR), β-cell function (HOMA-B), insulin sensitivity (HOMA-S), and fasting insulin for identifying the subjects with type 2 diabetes mellitus (T2DM) in Iranian adults using data from a prospective population-based study.

METHODS

From participants of Tehran Lipid and Glucose Study, 4942 Iranian subjects, aged 20-86 years, were followed for incident T2DM. Fasting serum insulin was determined by the electrochemiluminescence immunoasaay. The associations between HOMA-IR, HOMA-B, HOMA-S, and fasting insulin and incident T2DM were evaluated using Cox proportional hazards models. The receiver operator characteristic curve analysis was used to determine the cut-off points of HOMA-IR, HOMA-B, HOMA-S, and fasting insulin.

RESULTS

After 9.2 year follow-up, 346 (7.0 %) incident cases of T2DM were identified; the risk-factor-adjusted hazard ratios for HOMA1-IR, HOMA2-IR, HOMA1-B, HOMA2-B, HOMA1-S, HOMA2-S, and insulin were 1.15, 1.70, 0.732, 0.997, 0.974, 0.986, and 1.01 in women and 1.37, 1.67, 0.588, 0.993, 0.986, 0.991, and 1.06 in men, respectively (all p < 0.05 except for HOMA2-B in women). Optimal cut-off points for HOMA1-IR, HOMA2-IR, HOMA1-B, HOMA2-B, HOMA1-S, HOMA2-S, and insulin were 1.85, 1.41, 86.2, 72.5, 54.1, 63.7, and 11.13 µU/ml in women and 2.17, 1.18, 67.1, 74.6, 46.1, 74.1, and 9.16 µU/ml in men, respectively.

CONCLUSIONS

HOMA-IR, HOMA-B (except for HOMA2-B in women), HOMA-S, and fasting insulin were independent predictors of T2DM. Optimal cut-off points of HOMA-IR, HOMA-B, HOMA-S, and fasting serum insulin were determined from a population-based study for identifying incident T2DM.

Insulin sensitivity and secretion in youth onset type 2 diabetes with and without visceral adiposity

AIM

To investigate insulin sensitivity and insulin secretion patterns among Asian Indian youth without and with type 2 diabetes (T2DM-y defined as onset of diabetes at or below 25 years) with normal and high visceral fat (VF) levels.

METHODS

We recruited 74 T2DM-y individuals, within 18 months of diagnosis and compared them to 77 age-matched controls with normal glucose tolerance (NGT). Using L4/L5 abdominal CT images, VF levels were categorized as normal or high according to their median values. Oral glucose tolerance tests (glucose and insulin measures) were used to derive Matsuda index, insulin resistance (HOMA-IR) and oral disposition index (DIo). Relationships between measures of insulin sensitivity and secretion and T2DM-y by VF level were assessed using standardized multinomial regression models.

RESULTS

Participants were categorized into four groups: NGT-normal VF; NGT-high VF; T2DM-normal VF, and T2DM-high VF. Among NGTs, those with high VF had significantly lower insulin sensitivity (0.013 vs.0.019 pM(-1)) and Matsuda index (10.2 vs.13.8), than normal VF. When compared, T2DM-high VF had lowest insulin sensitivity (0.009 vs.0.019, 0.013, 0.012 pM-1; p<0.001), Matsuda index (6.4 vs. 13.8, 10.2, 8.6; p<0.001), OGIS120 (305 vs. 396, 382, 316; p<0.001) and DIo (0.48 vs. 3.75, 3.20, 0.55 mmol/L; p<0.001). At every category of 2 h PG values, NGT-high VF had lower DIo than NGT-normal VF participants. In standardized multinomial models, that included DIo and Matsuda index adjusted for age, gender, BMI, and leptin, DIo (Odds ratio: 0.001; 95%Confidence interval: 0.000-0.020), matsuda index (0.26; 0.07-0.93), age (2.92; 1.18-7.19) and leptin (3.17; 1.12-8.99) were associated with high VF among T2DM.

CONCLUSION

Lower DIo and Matsuda index, younger age and higher leptin were independently associated with high visceral fat among T2DM participants. Also, lower DIo was seen with increasing 2 h PG values even among normal glucose tolerant individuals.

Abrogation of adenosine A1 receptor signalling improves metabolic regulation in mice by modulating oxidative stress and inflammatory responses

AIMS/HYPOTHESIS

Adenosine is an important regulator of metabolism; however, the role of the A1 receptor during ageing and obesity is unclear. The aim of this study was to investigate the effects of A1 signalling in modulating metabolic function during ageing.

METHODS

Age-matched young and aged A 1 (also known as Adora1)-knockout (A1(-/-)) and wild-type (A1(+/+)) mice were used. Metabolic regulation was evaluated by body composition, and glucose and insulin tolerance tests. Isolated islets and islet arterioles were used to detect islet endocrine and vascular function. Oxidative stress and inflammation status were measured in metabolic organs and systemically.

RESULTS

Advanced age was associated with both reduced glucose clearance and insulin sensitivity, as well as increased visceral adipose tissue (VAT) in A1(+/+) compared with A1(-/-) mice. Islet morphology and insulin content were similar between genotypes, but relative changes in in vitro insulin release following glucose stimulation were reduced in aged A1(+/+) compared with A1(-/-) mice. Islet arteriolar responses to angiotensin II were stronger in aged A1(+/+) mice, this being associated with increased NADPH oxidase activity. Ageing resulted in multiple changes in A1(+/+) compared with A1(-/-) mice, including enhanced NADPH oxidase-derived O2(-) formation and NADPH oxidase isoform 2 (Nox2) protein expression in pancreas and VAT; elevated levels of circulating insulin, leptin and proinflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-12); and accumulation of CD4(+) T cells in VAT. This was associated with impaired insulin signalling in VAT from aged A1(+/+) mice.

CONCLUSIONS/INTERPRETATION

These studies emphasise that A1 receptors regulate metabolism and islet endocrine and vascular functions during ageing, including via the modulation of oxidative stress and inflammatory responses, among other things.

Optimal Waist Circumference Cutoff Value Based on Insulin Resistance and Visceral Obesity in Koreans with Type 2 Diabetes

BACKGROUND

Visceral obesity is the most powerful contributor to the development of metabolic syndrome (MetS) and cardiovascular diseases. In light of visceral obesity, however, there is a paucity of data on the appropriate cutoff point of waist circumference (WC) in subjects with type 2 diabetes. The aim of this study was to investigate the optimal cutoff value for WC that signals insulin resistance (IR) and visceral obesity in Koreans with type 2 diabetes.

METHODS

We evaluated 4,252 patients with type 2 diabetes (male 2,220, female 2,032, mean age 57.24 years) who visited our clinic between January 2003 and June 2009. WC was measured at the midpoint between the lower rib and the iliac crest, and insulin sensitivity was assessed by the rate constant of plasma glucose disappearance (Kitt %/min) using an insulin tolerance test. Visceral fat thickness was measured using ultrasonography. Statistical analysis was performed using receiver operating characteristic curve.

RESULTS

The optimal cutoff points for WC for identifying the presence of IR and visceral obesity, as well as two or more metabolic components, were 87 cm for men and 81 cm for women. Moreover, these cutoff points had the highest predictive powers for the presence of visceral obesity. The MetS defined by new criteria correlated with the increased carotid intima-media thickness in female subjects.

CONCLUSION

Our results suggest that the optimal cutoff values for WC in Koreans with type 2 diabetes should be reestablished based on IR and visceral obesity.

HOMA-IR Values are Associated With Glycemic Control in Japanese Subjects Without Diabetes or Obesity: The KOBE Study

BACKGROUND

Several studies have reported that insulin resistance was a major risk factor for the onset of type 2 diabetes mellitus in individuals without diabetes or obesity. We aimed to clarify the association between insulin resistance and glycemic control in Japanese subjects without diabetes or obesity.

METHODS

We conducted a community-based cross-sectional study including 1083 healthy subjects (323 men and 760 women) in an urban area. We performed multivariate regression analyses to estimate the association between the homeostasis model assessment of insulin resistance (HOMA-IR) values and markers of glycemic control, including glycated haemoglobin (HbA1c), 1,5-anhydroglucitol (1,5-AG), and fasting plasma glucose (FPG) levels, after adjustment for potential confounders.

RESULTS

Compared with the lowest tertile of HOMA-IR values, the highest tertile was significantly associated with HbA1c and FPG levels after adjustment for potential confounders, both in men (HbA1c: β = 1.83, P = 0.001; FPG: β = 0.49, P < 0.001) and women (HbA1c: β = 0.82, P = 0.008; FPG: β = 0.39, P < 0.001). The highest tertile of HOMA-IR values was inversely associated with 1,5-AG levels compared with the lowest tertile (β = -18.42, P = 0.009) only in men.

CONCLUSIONS

HOMA-IR values were associated with markers of glycemic control in Japanese subjects without diabetes or obesity. Insulin resistance may influence glycemic control even in a lean, non-diabetic Asian population.

Genetic Variants Associated With Quantitative Glucose Homeostasis Traits Translate to Type 2 Diabetes in Mexican Americans: The GUARDIAN (Genetics Underlying Diabetes in Hispanics) Consortium

Insulin sensitivity, insulin secretion, insulin clearance, and glucose effectiveness exhibit strong genetic components, although few studies have examined their genetic architecture or influence on type 2 diabetes (T2D) risk. We hypothesized that loci affecting variation in these quantitative traits influence T2D. We completed a multicohort genome-wide association study to search for loci influencing T2D-related quantitative traits in 4,176 Mexican Americans. Quantitative traits were measured by the frequently sampled intravenous glucose tolerance test (four cohorts) or euglycemic clamp (three cohorts), and random-effects models were used to test the association between loci and quantitative traits, adjusting for age, sex, and admixture proportions (Discovery). Analysis revealed a significant (P < 5.00 × 10(-8)) association at 11q14.3 (MTNR1B) with acute insulin response. Loci with P < 0.0001 among the quantitative traits were examined for translation to T2D risk in 6,463 T2D case and 9,232 control subjects of Mexican ancestry (Translation). Nonparametric meta-analysis of the Discovery and Translation cohorts identified significant associations at 6p24 (SLC35B3/TFAP2A) with glucose effectiveness/T2D, 11p15 (KCNQ1) with disposition index/T2D, and 6p22 (CDKAL1) and 11q14 (MTNR1B) with acute insulin response/T2D. These results suggest that T2D and insulin secretion and sensitivity have both shared and distinct genetic factors, potentially delineating genomic components of these quantitative traits that drive the risk for T2D.

Associations between ultrasound measures of abdominal fat distribution and indices of glucose metabolism in a population at high risk of type 2 diabetes: the ADDITION-PRO study

Aims

Visceral adipose tissue measured by CT or MRI is strongly associated with an adverse metabolic risk profile. We assessed whether similar associations can be found with ultrasonography, by quantifying the strength of the relationship between different measures of obesity and indices of glucose metabolism in a population at high risk of type 2 diabetes.

Methods

A cross-sectional analysis of 1342 participants of the ADDITION-PRO study. We measured visceral adipose tissue and subcutaneous adipose tissue with ultrasonography, anthropometrics and body fat percentage by bioelectrical impedance. Indices of glucose metabolism were derived from a three point oral glucose tolerance test. Linear regression of obesity measures on indices of glucose metabolism was performed.

Results

Mean age was 66.2 years, BMI 26.9kg/m², subcutaneous adipose tissue 2.5cm and visceral adipose tissue 8.0cm. All measures of obesity were positively associated with indicators of glycaemia and inversely associated with indicators of insulin sensitivity. Associations were of equivalent magnitude except for subcutaneous adipose tissue and the visceral/subcutaneous adipose tissue ratio, which showed weaker associations. One standard deviation difference in BMI, visceral adipose tissue, waist circumference, waist/height ratio and body fat percentage corresponded approximately to 0.2mmol/l higher fasting glucose, 0.7mmol/l higher 2-hr glucose, 0.06-0.1% higher HbA1c, 30 % lower HOMA index of insulin sensitivity, 20% lower Gutt’s index of insulin sensitivity, and 100 unit higher Stumvoll’s index of beta-cell function. After adjustment for waist circumference visceral adipose tissue was still significantly associated with glucose intolerance and insulin resistance, whereas there was a trend towards inverse or no associations with subcutaneous adipose tissue. After adjustment, a 1cm increase in visceral adipose tissue was associated with ~5% lower insulin sensitivity (p≤0.0004) and ~0.18mmol/l higher 2-hr glucose (p≤0.001).

Conclusion

Visceral and subcutaneous adipose tissue assessed by ultrasonography are significantly associated with glucose metabolism, even after adjustment for other measures of obesity.