Obesity is the Most Important Factor for Gender Inequality in Type 2 Diabetes Incidence in an Iranian Population

Abstract

Background: The results of Shahroud Eye Cohort Study (ShECS) showed a high 5‑year incidence
of diabetes mellitus with female predominance in 40–64 years old Iranian population. The
aim of this report was to decompose the observed sex differences in the incidence of diabetes.

Methods: Sex‑specific incidence rate of diabetes was calculated between the two phases of ShECS
(2009–2014). The gap decomposition was done by the twofold Blinder–Oaxaca decomposition
model.

Results: The results showed that from the total gap (11.19%–15.55% = -4.36%) between
the two sexes, 3.46% which forms 79.4% of the total gap is related to the difference in obesity in
both genders. In contrast to obesity, age and overweigh status had a decreasing influence on gender
inequality.

Conclusions: Obesity of Iranian women compared with men is the most important reason
for an increase in the incidence of diabetes in women.

Keywords: Diabetes mellitus, incidence rate, Iran, Blinder–Oaxaca decomposition, Obesity