Large-scale clinical data of Japanese residents suggests that the pace of increasing Body Mass Index (BMI) in diabetic patients is similar to that in healthy individuals. Results from the study published in the journal BMC Public Health also indicate that the BMIs of the Japanese patients do not significantly increase before diabetes onset. The worldwide population of individuals with diabetes is more than 382 million people, and approximately 20.5 million of these are in Japan.
Because of subsequent ischemic heart disease, cerebral infarction, retinopathy, nephropathy, and neuropathy are life threatening to numerous people, the prevention of diabetes is of great importance. Among many environmental factors associated with diabetes, obesity is a particularly well-known risk factor for type 2 diabetes.
Several studies have indicated that individuals with high BMIs are at a high risk of developing diabetes, however, due to their cross-sectional or 2–3 time-point cohort designs, these reports have not distinguished the risk of “increasing BMI” on diabetes onsets from that of “high BMI per se.”
In the study, Hiroshi Yokomichi from the Department of Health Sciences, Division of Medicine, Graduate School Department of Interdisciplinary Research, University of Yamanashi in Japan and colleagues retrospectively compared BMI trajectories of individuals with and without diabetes in a case-control design to assess whether increasing BMI alone would be a risk factor.
The researchers comprehensively measured health data over ten years to understand the trajectories of BMIs among diabetic patients and healthy subjects. The results showed that the mean ages in male patients and controls was 59.3 years and 57.7 years, whereas the mean BMIs were 25.0 kg/m 2 and 25.2 kg/m 2, respectively. In female patients and controls, the mean ages were 61.4 years and 60.1 years, whereas the mean BMIs were 24.8 kg/m 2 and 24.9 kg/m 2, respectively.
The researchers found no differences of increasing BMIs between the group of patients and the control group in males and females. However, increases in BMI were observed in both male and female patients in comparison to BMIs 1 year before the onset of diabetes.
Based on the results, the researchers suggest that the body weight of some patients with type 2 diabetes increases immediately before disease onset. Therefore, healthy but pre-diabetic individuals whose body weight has been increasing for the past few years should receive proactive guidance regarding diet and exercise from their physicians, and they should be encouraged to control their body weight.