Background: Type 2 diabetes mellitus (T2DM) is associated with a 2-4 fold increased risk of cardiovascular disease (CVD) but there are limited data assessing the effect of gender on this association.
Aim: To investigate gender differences in CVD risk factors and mortality in T2DM.
Patients and Methods: The longitudinal observational Fremantle Diabetes Study Phase I included 1,296 T2DM subjects recruited from 1993 to 1996. This cohort and 5,159 age-, gender-, and postcode-matched non-diabetic residents were followed for validated outcomes to death/census at end-2010. Cox proportional hazards modelling, with age as the timeline, was used to determine the effect of sex on CVD mortality amongst the T2DM cohort after adjusting for other independent variables.
Results: At baseline, the T2DM patients had a mean±SD age of 64.0±11.3 years, 49% were male, and their median diabetes duration was 4.0 years. During 15,527 person-years of follow-up, 654 (348 men) died vs 1,958 (1,079 men) non-diabetic residents during 69,489 person-years. For men, respective CVD mortality rates (95% CI) were 23 (19-26) and 10 (9-11) per 1,000 patient-years, with a mortality rate ratio (MRR) of 2.26 (1.86-2.74). For women, the comparative rates and ratio were 18 (15-21) and 8 (7-9) per 1,000 patient-years, and 2.23 (1.82-2.72). The CVD MRR for men vs women with T2DM was 1.28 (1.02-1.59) compared with 1.26 (1.07-1.47) for matched non-diabetic residents. After adjusting for Aboriginal background, current smoking, HbA1c, loge(total:HDL cholesterol ratio), loge(urinary albumin:creatinine ratio), eGFR<60 ml/min/1.73m2, peripheral neuropathy, retinopathy, IHD and PAD in Cox models, men with T2DM were 1.94 times more likely to die from CVD than women.
Conclusions: Australian women with T2DM have the same increased relative risk of CVD death vs matched non-diabetic individuals as that for men with T2DM. However, consistent with general population, women with T2DM have a more favourable CVD outcome than men with T2DM.