The relationship between objectively measured physical activity and parameters of disease control in an African population of type 2 diabetes mellitus
Background: The incidence of type 2 diabetes mellitus (T2DM) is increasing rapidly. This is possibly due to increasing obesity, reduced level of activity, sedentary lifestyle, ageing population and industrialisation.
Aim: The primary objective of this study was to ascertain the level of activity using a pedometer. The secondary objectives were: (1) to correlate the baseline level of activity with body mass index (BMI), HbA1c and blood pressure (BP), (2) to assess whether 7 000 steps a day influence HbA1c and BP over a three-month period.
Method: A total of 110 patients were screened; 95 patients (n = 95) completed the study. At the first visit HbA1c, BMI and BP were measured. At the end of the first month baseline physical activity was recorded using pedometers. Patients were divided into two groups: active (n = 50) and control (n = 45). Patients in the active group were asked to walk a minimum of 7 000 steps/day. The control group were asked to continue their usual activity. These patients were followed up monthly over a period of three months. At each visit BMI, BP and step counts were recorded. HbA1c was measured only at the first and last visit.
Result: Activity levels increased significantly in the active group throughout the study. Mean step count for the control group at baseline was 2 923.1 ± 1 136.9, which increased to 3 431.2 ± 1 251.7 by the end of the study. Mean step count for the active group at baseline was 4 609.9 ± 1 702.1, which increased to 7 244.8 ± 1 419.4 by the end of the study. The difference between control and active group was statistically significant (p < 0.001). Systolic and diastolic BP decreased significantly in both groups (p = 0.017) for systolic BP and (p = 0.002) for diastolic BP but no interaction was found between the groups as systolic and diastolic BP decreased at the same rate over time in both groups. HbA1c decreased by 1.04% in the active group; this difference was statistically highly significant (p < 0.001).
Conclusion: Increase in activity levels decreases HbA1c by 1.04 percentage point over three months in T2DM (p < 0.001), which is statistically significant.
Keywords: BMI, HbA1c, pedometers, physical activity, T2DM