This study evaluated trends in cardiovascular risk factors among people with diabetes. Data obtained as part of the Health Survey for England (HSE) between 1994 and 2009 were examined with particular focus on the differences between men and women and between social classes. It was important to investigate possible trends so that the impact of developments in service provision and health promotion could be assessed.
Among people with diabetes in England, have there been changes in cardiovascular risk factors between 1994 and 2009? Are there differences between men and women, and between different social classes in cardiovascular risk factors over the period of time studied?
The outcomes of interest were blood pressure (BP), cholesterol, smoking, BMI, and glycated haemoglobin (HbA1c).
Participants in the HSE were recruited using a multistage cluster sampling technique. This method can result in a sample which is more representative of the population in comparison to a sampling technique which does not refine the target sample.
Risk factors were measured using accepted units and equipment. However measurement methods changed over time in the case of cholesterol and HbA1c.
Across the surveys the mean age of participants ranged from 61.2 years to 64.5 years. The total sample size ranged from 12,197 in 1994 to 3840 in 2009. [S2] More women took part in each survey than men, and more non-manual than manual workers.
There was an increase in the prevalence of diabetes across the study period which was consistently higher among men and among manual workers.
Amongst pople with diabetes, significant improvements in levels of cardiovascular risk factors were found:
|Risk factor||Change from 1994 to 2009
||Annual change (95% CI )|
|Blood pressure||Systolic BP: 148mmHg to 137 mmHgDiastolic BP: 80 mmHg to 70 mmHg||-0.82 mmHg (-0.98 to -0.67)-0.64 mmHg (-0.73 to -0.55)|
|Mean total cholesterol||6.1mmol/L to 4.5mmol/L||-0.12 mmol/l (-0.13 to -0.11)|
|Smoking||17.5% to 13.4%||Odds of smoking per year: 0.97 (0.95 to 0.99)|
|BMI||27.7 kg/m2 to 31.6 kg/m2||0.24, 0.2 to 0.28|
|HbA1c||Ranged between 7.3% and 7.5%||DNA|
There was no significant change in the proportion of patients reaching target HbA1c.
This high quality study shows that substantial gains have been achieved in terms of cardiovascular risk factors among people with diabetes in England. The reductions in blood pressure and cholesterol across the sample and in smoking among women and non-manual social classes may protect people with diabetes from cardiovascular disease.
Although difficult to achieve, this sample has maintained very respectable mean HbA1c values which indicates individuals are performing self-management very well.
Increases in BMI stand out as the greatest threat to cardiovascular health among people with diabetes.
- The diagnostic threshold for diabetes was changed in England in 2000. The increased prevalence of diabetes and reduction in cardiovascular risk factors may be influenced by increased detection amongst “healthier” patients.
- Response rates to the HSE declined over the study period
- The age range of the sample is quite narrow
- We don’t know how many participants had type 1 diabetes or type 2 diabetes
- Since this sample can be considered highly representative of the population in England, the results are likely to reflect local populations of older adults with diabetes
- Awareness of areas where gains have been made, such as improvements in cholesterol levels as well as problem areas, BMI in this case, can inform local service provision and policy making related to healthy eating and physical activity for weight loss.
Samaranayaka S & Gulliford MC. Trends in cardiovascular risk factors among people with diabetes in a population based study, Health Survey for England 1994–2009. Primary Care Diabetes 2013; 7:193-8.
Most recent data for the Health Survey for England 2011 can be found on the Health and Social Care Information Centre.