Comparison of risk factors between people with type 2 diabetes and matched controls in Nairobi, Kenya

Objective
To identify risk factors associated with type 2 diabetes (T2D) in Nairobi, Kenya.

Methods
A case–control study comparing 70 (53% women) recently diagnosed T2D cases with age-, sex- and socioeconomic status-matched normoglycemic controls (1:1). Objectively measured data were obtained on anthropometrics, handgrip strength and physical activity (by accelerometer). Self-reported data were collected on demographic characteristics and lifestyle factors. Logistic regression models, adjusted for covariates, were used to analyse the data.

Results
Each standard deviation (SD) increase in height was associated with lower odds for T2D (adjusted odds ratio (AOR) = 0.34 (95% confidence intervals [CIs] 0.17, 0.66), P = 0.0031). Fat-free mass was inversely associated with T2D (AOR = 0.42 (95% CI 0.24, 0.75), P = 0.0032, per SD increase). Grip strength was associated with a lower risk of T2D (AOR = 0.20 (95% CI 0.08, 0.45), P < 0.001, per SD increase). BMI was not associated with T2D, but higher waist-to-hip ratio was associated higher odds of T2D (AOR = 2.28 (95% CI 1.38, 3.79), P = 0.0014, per SD increase). Physical activity was not associated with T2D. Cases reported higher intakes of fruits and vegetables and a lower intake of sugar than controls.

Conclusions
Central obesity, rather than BMI, may have more utility for T2D risk stratification in Kenya, and interventions that increase muscle mass and strength, as well as support weight loss, may be useful for T2D prevention in this and other SSA populations. However, more evidence is needed to determine whether low muscle mass, strength and height are causally related to T2D risk and/or are indicators of adverse early-life environment.