Endocrine Abstracts

Objective: Diabetes mellitus (DM) is known to be associated with a lower trabecular bone score (TBS) and an increased risk of fracture. However, little is known regarding whether it is associated with poor bone results in pre-diabetic individuals. Despite the fact that both IFG and IGT are characterized by insulin resistance and β-cell dysfunction, the metabolic abnormalities are quite distinct between the two disorders. Impaired fasting glucose (IFG) was marked by dysfunctional insulin secretion and decreased hepatic insulin sensitivity. In contrast, impaired glucose tolerance (IGT) was related with decreased whole-body insulin sensitivity, followed by a decline in β-cell function. We examined if TBS differed depending on the prediabetes phenotype.

Methods: This was a cross-sectional analysis of baseline data collected from 30- to 64-year-old participants in the Study of the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) Cohort Study. A whole-body dual-energy X-ray absorptiometry (DXA) scan and an oral glucose tolerance test were performed. Excluding those with diabetes, liver cirrhosis, chronic kidney disease, or cancer, as well as those on osteoporosis drugs, steroids, or thyroid hormones, or who had ever received hormone replacement treatment, we enrolled 3.276 individuals. Subjects were classified as having normal glucose tolerance (NGT), isolated IFG, isolated IGT, or combined IFG and IGT (IFG+IGT). Statistical analyses were conducted by dividing into three groups (male, premenopausal women and postmenopausal women).

Results: Males with isolated IGT exhibited a lower TBS after adjusting for age, weight, vitamin D, Hba1c, cigarette smoking, and alcohol intake (1.466 vs 1.494, P=0.040). However, statistical significance disappeared when visceral fat was additionally adjusted for. In premenopausal women, patients with isolated IFG had a lower TBS than those with NGT (1.493 vs 1.513, P=0.044), and statistical significance was preserved even after visceral fat was further adjusted. There were no significant differences in TBS among groups of postmenopausal women.

Conclusion: Similar to diabetics, prediabetics have decreased TBS levels compared to NGT people. However, there were gender disparities in the association between TBS and prediabetes. Insulin resistance with visceral fat may have a greater impact on TBS in men, but disruption in insulin secretion may have a greater impact on TBS in premenopausal women.