Multi-ethnic differences in HbA_1c, blood pressure, and low-density-lipid cholesterol control among South Africans living with type 2 diabetes, after a 4-year follow-up

Abstract

Purpose

Our study set out to examine if disparities in control of glycated hemoglobin (HbA_1c), blood pressure (BP), and low-density-lipoprotein cholesterol (LDL-C) existed among an urban multi-ethnic cohort of South Africans, living with type 2 diabetes mellitus (T2DM).

Patients and methods

This longitudinal, retrospective study consisted of 261 men and women with previously diagnosed T2DM who attended Charlotte Maxeke Johannesburg Academic Hospital, South Africa across two time periods 2009 and 2013. Demographic and clinical data were extracted from consecutive medical records. The primary outcome was to determine achievements in HbA_1c, BP, and LDL-C among ethnic groups using evidence-based goals.

Results

The mean age of the cohort was 64 (±10.6) years, females represented 55%, and the self-reported diabetes duration was 16 (±10.6) years as at 2013. Black Africans (42.9%, n=112 of 261) were more likely to reach the HbA_1c target (<7%) and less likely to have had retinopathy, nephropathy, or cardiovascular disease. Over two-thirds of mixed-ancestry patients attained the BP target (<140/80 mmHg), while 90.2% of Caucasians achieved LDL-C goals (<2.5 mmol/L). Overall, across the ethnic groups studied, we found that HbA_1c control deteriorated over time, although BP levels remained the same and LDL-C levels drastically improved.

Conclusion

There was poor control of HbA_1c, BP, and LDL-C across all ethnic groups. Although a minority achieved recommended targets, some ethnic groups appeared to have worse control than others. Timely aggressive actions in particularly high-risk ethnic groups will prevent/delay the complications commonly associated with T2DM.

Keywords:

• diabetes mellitus
• ethnicity
• HbA_1c
• blood pressure
• LDL-C

Disclosure

The authors report no conflicts of interest in this work.