Although obesity could increase the risk of having type II diabetes mellitus, it is not always a direct link to the insulin-resistant disease. A recent study published in the February issue of Plos Medicine showed that most people who were diagnosed with type II diabetes did not get the disease until they have been obese or overweight for certain years. Some of the subjects who maintained their overweight levels gradually developed type II diabetes mellitus without a significant rise in their insulin resistance levels prior to the disease onset.
Dorte Vistisen, Kristine Færch, and colleagues from the Steno Diabetes Center in Gentofte in Denmark analyzed data from just over 6,700 participants of the Whitehall II cohort, which is a group of civil servants in London. From 1991 to 2009 for a median of about 14 years, these men and women, who were all White and had no type II diabetes mellitus when they first participated in the study, were followed by the researchers with 5-year clinical examinations. Only 645 people developed type II diabetes mellitus — about 9.6 percent of the sample population.
Vistisen and colleagues identified three significant patterns among those who developed type II diabetes. The first and largest group was called “stable overweight,” referring to those who were consistently overweight throughout the study. Fifteen of these people were called “progressive weight gainers,” meaning that they had a large insulin resistance over the years that led up to their present condition and diagnosis. The third group was called, “persistently obese,” which is made up of 26 people who were obese throughout the study. Even though they did not have significant insulin resistance, some of their beta cells in the pancreas that produced insulin had loss their function.
The study is limited to the Caucasian population in the U.K., and the researchers noted that a “great majority of patients had modest weight gain prior to diagnosis.” They suggested that health care providers should focus on small weight reductions for the larger populations than focusing mostly on weight loss for those at high-risk for type II diabetes. A more diverse study in a heterogeneous society is needed to reaffirm or refute the researchers’ findings.
Sometimes environmental factors, not always obesity, are the link to some cases of type II diabetes mellitus, according to a German study published in PLOS One on February 27, 2014. Researchers Werner Maier and colleagues wanted to examine if socio-economic status could play a major role in influencing the risk of getting type II diabetes in Germany. Almost 33,700 people over the age of 30 were analyzed based on a health survey called “GEDA” (Gesundheit in Deutschland Aktuell, or German Health Update) that was collected in 2009 and 2010. Among all men and women living in the most deprived areas, about 8.6 percent had type II diabetes mellitus and almost 17 percent were obese. In the least deprived areas, almost 6 percent of the sample population had type II diabetes mellitus and almost 14 percent were obese.
For women, lower educational levels and higher incidences of deprivation were both independently associated with higher rates of type II diabetes mellitus and obesity. Men were found to have a similar association but not for diabetes. Therefore, researchers highly recommend that such environmental factors must be addressed to prevent higher rates of diabetes and obesity.
Based on the current evidence, obesity is sometimes — not always — a predictor or a link to type II diabetes mellitus. Public health educators and health care professionals should look beyond just the diet, exercise, and drug interventions for treating and preventing obesity and diabetes. To address the worldwide obesity epidemic, a focus on addressing socio-economic, political, and environmental issues could instigate a chain reaction that influences people’s lifestyle and choices about food.
By Nick Ng
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