Circulating 25-hydroxyvitamin D is associated with insulin resistance cross-sectionally but not longitudinally in older adults: The Cardiovascular Health Study

Abstract

Background Despite extensive study, the role of vitamin D in insulin resistance and secretion remains unclear. Objective To examine the cross-sectional and longitudinal relationships between 25-hydroxyvitamin D (25(OH)D) concentrations and indices of insulin resistance and secretion in older adults. Methods and Results Among 2134 participants of the Cardiovascular Health Study who were free from cardiovascular disease, we measured serum 25(OH)D concentrations in samples collected in 1992–1993. We examined insulin resistance and secretion using Homeostasis Model Assessment (HOMA) estimates cross-sectionally and among 1469 participants who had repeated HOMA measures four years later (1996–1997). In cross-sectional analysis, each 10 ng/mL increment in 25(OH)D concentration was associated with a 0.09 lower adjusted HOMA-IR [95%CI (−0.17, −0.02), p=0.01]. However, baseline 25(OH)D concentrations were not associated with change in HOMA-IR over 4 years of follow up (p=0.48). 25(OH)D concentrations were not associated with insulin secretion, as determined by HOMA-β, in either cross-sectional or longitudinal analysis. Conclusions Circulating 25(OH)D concentrations are associated with lower insulin resistance in cross-sectional but not longitudinal analyses. Whether this reflects residual confounding in cross-sectional analyses or the short-term nature of the relationship between vitamin D and insulin sensitivity will require trials with repeated measures of these factors.

Low Vitamin D Serum Levels May Be a Modifiable Risk Factor for Obesity and Cognitive Impairment in Middle-Age Egyptian Women

“…Previous studies reported an association between obesity and insulin resistance [38,42]. The relation between insulin resistance and cognitive decline, especially memory impairment was mentioned in some studies [17].…”

Vitamin D deficiency in obesity and its relationship to insulin resistance and plasma leptin levels – preliminary study

“…Epidemiological studies showed correlations between low serum 25(OH)D concentration, an indicator of organism supply with vitamin D, and increased insulin resistance (10,11). Vitamin D may have effect on insulin resistance through direct action via VDR or indirectly via calcium and PTH levels.…”

Vitamin D and cardio-metabolic disease

“…In this regard, analyses of large cross-sectional and prospective cohorts may also provide valuable insights. In this issue of Metabolism , we publish results from the Cardiovascular Health Study that examined the cross-sectional and longitudinal relationships between 25(OH)D and indices of insulin resistance in a large cohort[24]. In over 1,400 relatively healthy adults, higher 25(OH)D concentrations displayed a cross-sectional association with lower HOMA-IR, however, they did not predict HOMA-IR over a four year follow-up.…”