Background Health inequalities exist in outcomes of diabetes in different socioeconomic groups and these are particularly marked for cardiovascular disease. This study explores the association between socioeconomic status (SES) and prevalence of cardiovascular risk factors (smoking, body mass index (BMI), glycated haemoglobin (HbA_1C), blood pressure and cholesterol) in people with type 2 diabetes in contemporary Scottish data.

Methods We performed a cross-sectional study of people with type 2 diabetes in Scotland who were alive on 30/6/16 identified from the population-based diabetes register. SES was defined using quintiles of the area-based Scottish Index of Multiple Deprivation (SIMD). Cardiovascular risk factors were defined as: current smoker, obesity (BMI ≥ 30 kg/m2), HbA_1C ≥ 58 mmol/mol, systolic blood pressure ≥ 140 mmHg, and cholesterol ≥ 5 mmol/l. Logistic regression models adjusted for age, sex, health board, history of cardiovascular disease, ethnicity and duration of diabetes were used to identify odds ratios (OR) (95% confidence intervals) for the most compared to the least deprived SIMD quintile for each risk factor.

Results There were 264,664 people with type 2 diabetes in the study population: mean (SD) age was 66.7 (12.8) years, 56.1% were male, 23.6% were in the most deprived quintile and 15.1% in the least deprived quintile. Less than 5% had missing data on key variables.

Crude prevalence of risk factors in the most/least deprived quintiles were 24.4/8.8% for smoking, 61.9/49.4% for obesity, 43.7/39.7% for above-target HbA_1C, 30.5/31.3% for above-target systolic blood pressure and 24.4/24.5% for above-target cholesterol.

Adjusted prevalence of current smoking (OR 3.25 (95% CI 3.09–3.42)), obesity (OR 1.59 (1.54–1.65)) and above-target HbA_1C (OR 1.13 (1.09-.17)) were higher in the most compared to the least deprived quintile. Adjusted prevalence of above-target systolic blood pressure was similar (OR 1.00 (0.97–1.04)), and of above-target cholesterol was lower in the most compared to the least deprived quintile (OR 0.85 (0.82–0.88)). Inequalities in current smoking were larger in females (OR 3.66 (3.37–3.96)) compared to males (OR 3.00 (2.81–3.19)). No other risk factors showed interactions between sex and SES.

Conclusion Socioeconomic deprivation is associated with significantly higher prevalence of smoking, obesity, and above-target HbA_1C among people with type 2 diabetes in Scotland. Inequalities in smoking status by SES among people with type 2 diabetes appear to have widened over time. Effective approaches to reducing these inequalities at both population and individual levels are required as well as reducing prevalence of risk factors across the whole population.