Sex differences in risk of incident microvascular and macrovascular complications: a population-based data-linkage study among 25 713 people with diabetes

Abstract

Background: The global prevalence of diabetes is similar in men and women; however, there is conflicting evidence regarding sex differences in diabetes-related complications. The aim of this study was to investigate sex differences in incident microvascular and macrovascular complications among adults with diabetes.

Methods: This prospective cohort study linked data from the 45 and Up Study, Australia, to administrative health records. The study sample included 25 713 individuals (57% men), aged ≥45 years, with diabetes at baseline. Incident cardiovascular disease (CVD), eye, lower limb, and kidney complications were determined using hospitalisation data and claims for medical services. Multivariable Cox proportional hazards models were used to assess the association between sex and incident complications.

Results: Age-adjusted incidence rates per 1000 person years for CVD, eye, lower limb, and kidney complications were 37, 52, 21, and 32, respectively. Men had a greater risk of CVD (adjusted hazard ratio (aHR) 1.51, 95% CI 1.43 to 1.59), lower limb (aHR 1.47, 95% CI 1.38 to 1.57), and kidney complications (aHR 1.55, 95% CI 1.47 to 1.64) than women, and a greater risk of diabetic retinopathy (aHR 1.14, 95% CI 1.03 to 1.26). Over 10 years, 44%, 57%, 25%, and 35% of men experienced a CVD, eye, lower limb, or kidney complication, respectively, compared with 31%, 61%, 18%, and 25% of women. Diabetes duration (<10 years vs ≥10 years) had no substantial effect on sex differences in complications.

Conclusions: Men with diabetes are at greater risk of complications, irrespective of diabetes duration. High rates of complications in both sexes highlight the importance of targeted complication screening and prevention strategies from diagnosis.

Keywords: CARDIOVASCULAR DISEASES; COHORT STUDIES; DIABETES MELLITUS; EPIDEMIOLOGY; RECORD LINKAGE.

Figure 1

(A) Age-adjusted incidence rates per 1000 person-years of incident diabetes-related complications by sex and (B) adjusted hazards ratio (aHR) (95% CI) for association between sex and incident diabetes-related complications. Hazards ratios are calculated from Cox proportional hazard models based on multiple imputed data adjusted for age, sociodemographics (education, SEIFA, income, language, country of birth, private insurance), lifestyle (BMI, smoking, diet and physical activity) and health history (family history of diabetes, cardiovascular disease, blood pressure and treatment for high cholesterol). BMI, body mass index; SEIFA, Socio-Economic Indexes for Areas.

Figure 2

Cumulative incidence of macrovascular and microvascular complications by sex: (A) CVD complications; (B) eye complications; (C) lower limb complications; (D) kidney complications. Hazard function survival curves using Kaplan-Meier methods. P values in the figures represent the results for the log-rank test. CVD, cardiovascular disease.