Researchers from the Drexel University School of Public Health found that patients who are both obese and vitamin D deficient are at greater risk of insulin resistance than patients with either factor alone.
Insulin resistance is a detrimental factor of type 2 diabetes, a condition that affects about 25 million adults in the US.
The researchers analyzed serum vitamin D levels from 5,806 participants from the National Health and Nutritional Examination Survey 2001-2006 (NHANES). They found that obese participants with adequate vitamin D levels had insulin resistance over 20 times more often than the overall study population. However, among participants who were both obese and vitamin D deficient, insulin resistance was about 32 times more common.
Lead author Shaum Kabadi, a doctoral candidate in epidemiology at Drexel states: “Our results suggest that the combination of these two factors increases the odds of insulin resistance to an even greater degree than would have been expected based on their individual contributions.”
Previous studies have shown that vitamin D and obesity independently increase the risk of insulin resistance and diabetes. This research is the first to support the finding that these two factors in combination further increase the risk of developing insulin resistance.
Senior author Dr. Longjian Liu, an associate professor in the School of Public Health, noted, “It’s not clear whether obesity itself causes a low vitamin D level or if it’s the other way around.”