Insulin Sensitivity and Ethnic Disparities in Metabolic Health

Insulin sensitivity—cells’ capacity to respond to insulin by taking up glucose—is a key determinant of metabolic health. Variations in insulin sensitivity among ethnic groups contribute to divergent risks of type 2 diabetes and related cardiometabolic disorders. These disparities arise from differences in body-fat distribution, ectopic lipid deposition in liver and muscle, and depot-specific mitochondrial function in adipose tissue. Genetic background, lifestyle and socioeconomic factors interact to shape insulin action, with certain populations exhibiting higher intramyocellular and hepatic fat despite comparable total adiposity. Elucidating these mechanisms underpins global strategies for personalised prevention and treatment, highlighting the importance of targeted interventions that address both systemic and tissue-level determinants of insulin resistance.

Research from Nature Portfolio

Recent studies have examined how exercise training induces depot-specific adaptations in subcutaneous adipose tissue to improve insulin sensitivity. In a cohort of obese black South African women, baseline measurements revealed that gluteal fat exhibited greater mitochondrial respiratory capacity and reactive oxygen species production than abdominal subcutaneous fat. A 12-week combined aerobic and resistance programme led to reduced ectopic lipid, lowered hydrogen peroxide release in both depots and enhanced systemic insulin sensitivity. Notably, exercise increased mitochondrial respiration in abdominal fat, correlating with reductions in body fat and redistribution of lipids. These findings underscore the therapeutic potential of structured physical activity to remodel adipose mitochondrial function and mitigate ethnic disparities in insulin action.

Insulin Sensitivity and Ethnic Disparities in Metabolic Health publication trend

The graph below shows the total number of articles in insulin sensitivity and ethnic disparities in metabolic health across all publications each year (not limited to Nature Index journals).

Technical terms

Insulin sensitivity: The efficiency with which target tissues respond to circulating insulin to promote glucose uptake and utilisation.

Ectopic fat: Lipid accumulation in non-adipose organs (for example, liver and muscle) that impairs insulin signalling.

Mitochondrial respiration: The process by which mitochondria consume oxygen to generate adenosine triphosphate, reflecting metabolic capacity of tissues.

Hyperinsulinaemic–euglycaemic clamp: A controlled infusion technique maintaining high insulin and normal glucose levels to measure whole-body and tissue-specific insulin sensitivity.

Visceral adipose tissue (VAT): Fat stored within the abdominal cavity around internal organs, strongly linked to insulin resistance and metabolic risk.

References

1. Exercise training results in depot-specific adaptations to adipose tissue mitochondrial function. Scientific Reports (2020).
2. Black African men with early type 2 diabetes have similar muscle, liver and adipose tissue insulin sensitivity to white European men despite lower visceral fat. Diabetologia (2019).
3. Fat redistribution and accumulation of visceral adipose tissue predicts type 2 diabetes risk in middle-aged black South African women: a 13-year longitudinal study. Nutrition & Diabetes (2019).
4. Increased risk for type 2 diabetes in relation to adiposity in middle-aged Black South African men compared to women. European Journal of Endocrinology (2022).