Insulin resistance in the middle-aged women with "Tigerish Back and Bearish Waist"

Body Composition Methods in Adults with Type 2 Diabetes or at Risk for T2D: a Clinical Review

PURPOSE OF REVIEW

The aim of this study is to summarize anthropometric and advanced methods used to assess body composition in adults diagnosed with type 2 diabetes (T2D) or at risk for T2D that provide clinically relevant information about T2D disease-related complications or risk factors.

RECENT FINDINGS

Anthropometry is commonly used in clinical settings; however, provides unreliable estimates of fat mass, fat-free mass, and body fat distribution for metabolic health assessments compared to advanced techniques such as bioelectrical impedance analysis (BIA), dual-energy x-ray absorptiometry (DXA), computerized tomography (CT), and magnetic resonance imaging (MRI). Few studies report the clinical use of anthropometric and advanced body composition methods that identify T2D disease-related complications or T2D risk factors. Anthropometry, BIA, DXA, CT, and MRI were used to estimate body adiposity and distribution, visceral and subcutaneous adipose tissue depots, and skeletal muscle mass. Review findings indicate that these methods were capable of identifying clinically relevant T2D disease-related complications such as sarcopenia and T2D risk factors such as obesity or regional adiposity. However, estimates were often sex and race/ethnicity specific warranting cross-validation of these methods in broader populations with T2D or risk for T2D prior to clinical implementation.

Greater Loss of Central Adiposity from Low-Carbohydrate versus Low-Fat Diet in Middle-Aged Adults with Overweight and Obesity

The objective of this study is to determine whether middle-aged adults prescribed a low carbohydrate-high fat (LCHF) or low fat (LF) diet would have greater loss of central fat and to determine whether the insulin resistance (IR) affects intervention response. A total of 50 participants (52.3 ± 10.7 years old; 36.6 ± 7.4 kg/m2 BMI; 82% female) were prescribed either a LCHF diet (n = 32, carbohydrate: protein: fat of 5%:30%:65% without calorie restriction), or LF diet (n = 18, 63%:13–23%: 10–25% with calorie restriction of total energy expenditure—500 kcal) for 15 weeks. Central and regional body composition changes from dual-x-ray absorptiometry and serum measures were compared using paired t-tests and ANCOVA with paired contrasts. IR was defined as homeostatic model assessment (HOMA-IR) > 2.6. Compared to the LF group, the LCHF group lost more android (15.6 ± 11.2% vs. 8.3 ± 8.1%, p < 0.01) and visceral fat (18.5 ± 22.2% vs. 5.1 ± 15.8%, p < 0.05). Those with IR lost more android and visceral fat on the LCHF verses LF group (p < 0.05). Therefore, the clinical prescription to a LCHF diet may be an optimal strategy to reduce disease risk in middle-aged adults, particularly those with IR.

Effects of combination of change in visceral fat and thigh muscle mass on the development of type 2 diabetes

AIM

We investigated the association between combined changes of visceral fat and thigh muscle over 5 years and incident type 2 diabetes in a prospective study of Japanese Americans.

METHODS

We followed 420 nondiabetic Japanese American subjects for 5 years and assessed visceral fat and thigh muscle by computed tomography (CT) at baseline and at 5 years. We categorized study subjects into 4 body composition change groups: visceral fat loss/thigh muscle gain (VF-loss/TM-gain), visceral fat loss/thigh muscle loss (VF-loss/TM-loss), visceral fat gain/thigh muscle gain (VF-gain/TM-gain), and visceral fat gain/thigh muscle loss (VF-gain/TM-loss) by combining changes from baseline in CT measured visceral fat and estimated thigh muscle areas. We fit a logistic regression model to examine the association between body composition categories and the development of incident type 2 diabetes at 5 years.

RESULTS

Cumulative incidence of type 2 diabetes was 9.8% at 5 years. VF-gain/TM-gain and VF-loss/TM-loss groups had higher risk for incident type 2 diabetes in a model adjusted for age, sex, family history of diabetes, and body mass index compared to VF-loss/TM-gain group as the reference category (OR=6.83 (1.85-25.17), 4.55 (1.06-19.48), respectively). However, the VF-gain/TM-loss group did not show a significant association with the odds of incident diabetes (3.24; 95% CI. 0.78-13.47).

CONCLUSIONS

Concordant gain or loss in visceral fat and thigh muscle was related to higher risk of incident type 2 diabetes compared to the reference combination of loss of visceral fat and gain of thigh muscle in Japanese Americans.

The association of insulin resistance and carotid atherosclerosis with thigh and calf circumference in patients with type 2 diabetes

Background

The relationship between body composition parameters such as thigh and calf circumference and insulin resistance or atherosclerosis in type 2 diabetes is poorly understood. The aim of this study was to investigate the relationship between insulin resistance, atherosclerosis, and thigh and calf circumference in patients with type 2 diabetes.

Methods

A total of 4,427 subjects with type 2 diabetes were enrolled in this study. Insulin sensitivity was assessed according the rate constant for plasma glucose disappearance (Kitt) determined via the short insulin tolerance test. Biochemical and anthropometric profiles were measured according to a standardized protocol. Visceral fat thickness and carotid intima media thickness (IMT) were measured by ultrasonography.

Results

Insulin sensitivity index (Kitt) was significantly correlated with weight adjusted thigh and calf circumference. Thigh circumference was inversely associated with IMT in men and women and calf circumference was negatively correlated with IMT in women. Multiple stepwise regression analysis revealed that thigh circumference was independently correlated with insulin sensitivity index (Kitt) and IMT. Furthermore, in multivariate logistic regression analysis, thigh circumference was an independent determinant factor for carotid atherosclerosis in patients with type 2 diabetes even after adjusting for other cardiovascular risk factors.

Conclusions

Thigh and calf circumference were correlated with insulin resistance and carotid atherosclerosis, and thigh circumference was independently associated with insulin resistance and carotid atherosclerosis in patients with type 2 diabetes.