The association between tobacco and alcohol use and health outcomes in individuals living with diabetes and prediabetes in South Africa: A cross-sectional study.

Background: Smoking and alcohol misuse are lifestyle factors that can be controlled and have significant health effects. Both these factors increase the risk of developing conditions such as diabetes mellitus because they affect glucose metabolism and can interfere with blood glucose control in individuals with diabetes. Research on tobacco and alcohol use and specific health outcomes among adults with prediabetes or type 2 diabetes mellitus (T2DM) could provide valuable information leading to more efficient treatment and management of this disease.

Objectives: To assess the association between tobacco and alcohol use and specific health outcomes among South African adults with prediabetes or T2DM.

Methods: Data from the 2016 South African Demographic and Health Survey were analysed using Stata v17. Participants were classified into prediabetes or T2DM groups, based on a glycated haemoglobin cut-off of 5.7% or self-report of a previous diagnosis of T2DM. Exposures of interest were self-reported current tobacco smoking and problem/risky alcohol use. The associations between these exposures and health outcomes in the different groups were assessed using multivariable logistic regression analysis. We adjusted for specific confounders in the regression models.

Results: Of a total of 6 108 participants (mean (standard deviation) age 41 (19) years), 72.2% (n=4 409) had prediabetes and 27.8% (n=1 699) T2DM; 17.7% (n=1 084) were current smokers and 9.3% (n=565) reported problem/risky alcohol use. Current smoking was significantly associated with 40% increased odds of shortness of breath (adjusted odds ratio (aOR) 1.40; 95% confidence interval (CI) 1.1 - 1.7; p<0.001) and 67% increased odds of chronic obstructive pulmonary disease (COPD)/asthma (aOR 1.67; 95% CI 1.2 - 2.2; p<0.001). Problem/risky alcohol use was significantly associated with 40% increased odds of COPD/asthma (aOR 1.40; 95% CI 1.1 - 1.7; p=0.001) and 92% increased odds of having cancer (aOR 1.92; 95% CI 1.5 - 2.5; p<0.001).

Conclusion: There is a need for targeted smoking cessation programmes and alcohol misuse counselling among individuals living with diabetes and prediabetes.