Overweight people with type 2 diabetes benefited from an intensive lifestyle intervention programme, losing weight and maintaining their weight loss, US research has shown in Archives of Internal Medicine.
Controlling blood glucose and cardiovascular risk factors is critical for people with type 2 diabetes to reduce their risks of developing complications, but less attention has been paid to lifestyle than pharmaceutical interventions, said the study authors – the Look AHEAD (Action for Health in Diabetes) Research Group. So they designed a randomized clinical trial into the effects of an intensive lifestyle intervention, compared with ‘standard’ diabetes support and education.
The researchers recruited 5,145 overweight or obese people with type 2 diabetes, whose mean age was 58.7 years. They assigned 2570 to the lifestyle intervention, a programme that combined diet modification and physical activity in order produce an intended 7% weight loss in the first year, and maintain it in subsequent years. This group was seen and contacted by phone at least once a month during the four-year study period. The other 2575 individuals were assigned to the diabetes support and education group, and were invited to three group sessions each year focusing on diet, physical activity and social support.
During the four-year study, individuals in the lifestyle intervention group lost – on average – a significantly greater proportion of their weight than people in the diabetes support group (6.2% compared with 0.9%). They also had greater improvements in fitness, HbA1c level, blood pressure and levels of high-density lipoprotein (HDL).
People in the diabetes support group had greater improvement in low-density lipoprotein (LDL), because of their greater usage of cholesterol-lowering medications.
The differences were largely maintained throughout the four-year study. By its end, the intervention group still had greater improvements in weight, fitness, HbA1c levels, systolic blood pressure and HDL levels than patients in the diabetes support group.
The authors say: “Although the differences between the two groups were greatest initially and decreased over time for several measures, the differences between the groups averaged across the four years were substantial and indicate that the intensive lifestyle intervention group spent a considerable time at lower cardiovascular disease risk.”
They add: “The critical question is whether the differences between groups in risk factors will translate into differences in the development of cardiovascular disease. These results will not be available for several additional years.
“However, effects of the magnitude that we observed for fitness, HDL-C and HbA1c levels and blood pressure have been associated with decreased cardiovascular events and mortality in previous medication trials and observational studies. Moreover, there may be long-term beneficial effects from the four-year period in which intensive lifestyle intervention participants have been exposed to lower cardiovascular disease risk factors, as seen in other clinical trials.”