Interleukin-6, tumour necrosis factor-alpha and insulin relationships to body composition, metabolism and resting energy expenditure in a migrant Asian Indian population

Authors


Elaine Rush, Auckland University of Technology, Private Bag 92006, Auckland 1128, New Zealand. Tel.: + 64 9 921 9999 x8091; Fax: + 64 9 921 9960; E-mail: elaine.rush@aut.ac.nz

Summary

Objective  Systemic inflammation and insulin resistance may play important roles in the pathogenesis of obesity-related diseases for which migrant Asian Indians are at particularly high risk. We examined relationships between markers of insulin resistance and inflammation, resting energy expenditure (REE), and body composition.

Design and methods  Measurements were made of total and regional body composition, including regional fat mass (FM) and appendicular skeletal muscle mass (ASMM) by dual-energy X-ray absorptiometry (DXA), REE by indirect calorimetry and fasting interleukin (IL)-6, tumour necrosis factor (TNF)-α, glucose and insulin, in 79 healthy Asian Indians (38F, 41M; age 30–49 years) from urban Auckland, New Zealand. Beta-cell function (HOMA B%) and insulin sensitivity (HOMA S%) were derived using homeostatic model assessment.

Results  Men had a more central distribution of body fat than women. REE was strongly correlated with IL-6 concentrations in men but not in women. In both sexes, IL-6 was associated positively with percentage body fat and HOMA B% and inversely with ASMM and HOMA S%. Insulin increased and HOMA S% decreased with increasing waist-to-hip ratio and abdominal-to-thigh fat ratio in men but not in women. TNF-α was not significantly associated with any of the variables examined.

Conclusion  Relationships between body fat distribution and HOMA S% were strongly sex dependent and may indicate a greater propensity for development of the metabolic syndrome among male Asian Indians than females in the age group examined.

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