JAMA study finds no difference in incident CVD events among women and men with type 1 diabetes

USA: Despite having a more favorable cardiometabolic risk factor profile than men, the incidence of CVD events was not significantly lower in women with type 1 diabetes than in men, according to a new study published in JAMA Network.

Women generally have a lower risk of cardiovascular disease (CVD) than men. However, the relative risk of CVD in those with type 1 or type 2 diabetes is comparable to or higher in women than in men. Uncertainty surrounds the precise causes of the decline in CVD risk in women with diabetes.

This study aimed to compare women and men with type 1 diabetes who participated in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) trial to determine the management of cardiometabolic risk variables and their relationship to CVD events.

Data from the combined DCCT (randomized clinical trial, done 1983–1993) and EDIC (observational study, conducted 1994–present) trials were used in this cohort analysis through April 30, 2018 (mean [SD] follow-up, 28.8 [5.8] years), across 27 clinical centers in the US and Canada. Between July 2021 and April 2022, data analysis was carried out. Patients were randomly allocated to receive intensive or conventional diabetes therapy during the DCCT phase. There were 1441 type 1 diabetic individuals in total (mean [SD] age at DCCT baseline, 26.8 [7.1] years; 761 [52.8%] men; 1390 [96.5%] non-Hispanic White). Cardiometabolic risk variables and CVD events were evaluated through a thorough medical history and targeted physical examination. Samples of blood and urine were analyzed centrally. A review committee made decisions regarding CVD incidents. To analyze sex differences in cardiometabolic risk variables and CVD risk over time, linear mixed models and Cox proportional hazards models were used.

Conclusive points of the trial:

• Women had significantly lower BMI (β = −0.43 [SE, 0.16]; P = .006), waist circumference, blood pressure (systolic: β = −5.77 mm Hg [SE, 0.35 mm Hg]; P < .001; diastolic: β = −3.23 mm Hg [SE, 0.26 mm Hg]; P < .001), and triglyceride levels (β = −10.10 mg/dL [SE, 1.98 mg/dL]; P < .001); higher HDL cholesterol levels and similar LDL cholesterol levels in comparison to men.
• In terms of blood pressure (i.e., <130/80 mm Hg: 90.0% vs 77.4%; P <.001) and triglycerides (i.e., <150 mg/dL: 97.3% vs 90.5%; P <.001), women met specified limits more frequently than men.
• Gender-specific HDL cholesterol levels (ie, ≥50 mg/dL for women, ≥40 mg/dL for men) were observed less (74.3% vs 86.6%; P < .001)
• Cardioprotective medications were used less commonly in women than men.
• Additionally, women were less likely to meet their targets for tighter glycemic control than men and had significantly higher pulse rates.

"Diabetes may be related to sex differences in the traditional classification of cardiometabolic risk factors, supporting the need to reevaluate clinical care and treatment recommendations based on sex," the researchers added.

In contrast to men, women had lower prevalence and mean levels of the majority of cardiometabolic risk variables, except for pulse rate and HbA1c. These outcomes indicate that women with type 1 diabetes should actively improve their management of CVD risk factors, concluded the authors.

REFERENCE

Braffett BH, Bebu I, El ghormli L, et al. Cardiometabolic Risk Factors and Incident Cardiovascular Disease Events in Women vs Men With Type 1 Diabetes. JAMA Netw Open. 2022;5(9):e2230710. doi:10.1001/jamanetworkopen.2022.30710