Although high BMI and visceral obesity are widely accepted risk factors for Type II Diabetes, a recent Chinese study showed that for a given waist circumference a larger hip circumference is protective against Diabetes. Hip circumference is a measure below the waist of the widest part/center of the hip. The study was based on similar results found in European studies (Swedish). The link to the article is at the bottom of the page.
So the question arises, why is a larger hip circumference protective against Diabetes?
Keep in mind that waist circumference is still a negative risk factor for Diabetes.
Could it be that larger hips are indicative of more peripheral adipose tissue than visceral (the Pear vs Apple body fat distribution) and the real reason of the protective effect is due to lower visceral fat?
The following video is a very nice overview of insulin signaling (GLUT-4 translocation, etc), and Diabetes (Type I vs. Type II, CTL kiss of death, etc):
Article
Hip Circumference and the Risk of Type 2 Diabetes in Middle-Aged and Elderly Men and Women: The Shanghai Women and Shanghai Men’s Health Studies By Baquyyah Conway et. al
Link: http://www.sciencedirect.com.ezproxy1.library.arizona.edu/science/article/pii/S1047279711000524
Based on my current knowledge of Type II Diabetes, I found the concept of this study quite contradictory, as it would be thought that if a large waist circumference (due to increased visceral adiposity) is characteristic for the onset of Type II Diabetes, then it would generally be assumed that a large hip circumference would be as well. Throughout reading the article, I found that their explanation for larger hip circumference being protective against Type II Diabetes is possibly attributed to "gluteofemoral subcutaneous fat functioning as a “metabolic sink.” Gluteofemoral (lower body) subcutaneous fat is essentially peripheral adiposity, and a metabolic sink is any process of the body that requires energy to occur. According to another article, gluteofemoral adipose tissue is a huge player in the production and regulation of the lipokine palmitoleate, which is an insulin-sensitizing lipokine, and also is suspected to suppress inflammation (DiabetesJournals). Type II Diabetes results due to decreased insulin sensitivity, causing high blood glucose levels. Therefore, people who have higher levels of gluteofemoral adipose tissue would produce more lipokine palmitoleate, which increases the insulin sensitivity of its effectors. By increasing insulin sensitivity of its effectors would allow more uptake of blood glucose, which therefore decrease their risk for Type II Diabetes.
ReplyDeleteInteresting!
http://diabetes.diabetesjournals.org/content/early/2012/04/03/db11-1810.abstract
You make some great points! One thing I would add, a more simple way of looking at it. For a given BMI, waist circumference measures above the hip at the lower abdomen and thus it measures not only subcutaneous but also intra-abdominal fat (visceral). On the other hand, hip circumference measures at a lower point away from the abdomen and the risks associated with intra abdominal (visceral) fat. Therefore, for the same BMI, a higher hip circumference would indicate greater amount of adipose tissue in the hips/thighs (peripheral obesity). Since, the BMI is the same as someone with lower hip circumference, the indication is that extra weight in the hips is compensated by a lower weight in the abdomen and thus lesser visceral fat which has been linked to numerous chronic conditions (diabetes, heart disease, hypertension, etc). Just another viewpoint into the study.
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