Lean BMI in Japanese with type 2 diabetes linked to lowest mortality

Japanese researchers have conducted a study that found patients with type 2 diabetes in the leanest body mass index (BMI) category had increased mortality rates.
Data was collected on 2,620 adults with type 2 diabetes and separated into two different studies; the Japanese Diabetes Complication Study and the Japanese Elderly Diabetes Intervention Trial.
Factors such as age, smoking, physical activity and other variables were considered, with patients divided into BMI categories of 14.4-18.5 kg/m2, 18.5-22.4 kg/m2, 22.5-24.9 kg/m2 and 25-37.5 kg/m2.
The researchers found that during a follow-up period of 6.3 years, there were 45 deaths in the 18.5-22.4 kg/m2 category. This was higher than any other BMI category, with a comparative 34 deaths in the heaviest weight category of 25-37.5 kg/m2.
Previously research has suggested that obesity plays a role in the low mortality of people with type 2 diabetes. These findings, however, provide interesting results that suggest obesity had no profound influence in the relationship to mortality.
In a statement, the research team wrote: “The mechanism underlying higher mortality among lean patients is unclear. A potential explanation is unintentional weight loss due to chronic inflammation.
“Furthermore, inflammation may be a manifestation of comorbidities of diabetes such as cardiovascular diseases, cancer and infectious diseases”.