Impaired Glucose Tolerance and Bone Mineral Content in Overweight Latino Children With a Family History of Type 2 Diabetes

Abstract

OBJECTIVE -Research on the skeletal status of pre-diabetic (type 2 diabetic) children is warranted. We examined the hypothesis that bone mineral content (BMC) and bone mineral density (BMD) will be lower in children with impaired glucose tolerance (IGT) versus normal glucose tolerance (NGT).RESEARCH DESIGN AND METHODS -Total body BMC and BMD of 184 overweight Latino children (106 boys, 78 girls, 11.9 Ϯ 1.7 years) with a family history of type 2 diabetes were measured using dual-energy X-ray absorptiometry. Glucose tolerance was assessed by 2-h glucose after an oral glucose tolerance test. Area under the insulin curve (AUC) assessed the cumulative insulin response to oral glucose. Acute insulin response to glucose (AIR) was determined by an intravenous glucose tolerance test.RESULTS -Partial correlations revealed an inverse relationship between BMC and AIR (r ϭ Ϫ0.29, P ϭ 0.00), AUC (r ϭ Ϫ0.28, P ϭ 0.00), fasting insulin (r ϭ Ϫ0.16, P ϭ 0.04), and 2-h insulin (r ϭ Ϫ0.16, P ϭ 0.04). There was no significant difference in BMC or BMD between children with IGT (n ϭ 46) or NGT (n ϭ 138). Stepwise multiple linear regression revealed that 89% of the variance in BMC is attributed to lean mass (87%), age (1%), and AIR (1%). BMD was explained by lean mass (69%), Tanner stage (3%), and AUC (2%).CONCLUSIONS -The findings of this study suggest that in overweight children, lean mass is the primary predictor of BMC and BMD, whereas age, Tanner stage, and the acute and cumulative insulin responses to oral glucose make subtle independent contributions to the total variances. In addition, poor glycemic control does not seem to be detrimental to bone mass of pre-diabetic children.

Influence of visceral and subcutaneous fat in bone mineral density of obese adolescents

“…In fact, adiponectin was associated with a protective effect against osteoporosis development (26,39). However, the concentration of this anti-inflammatory adipokine was reduced in obese adolescents and adults (40), which may partially explain why we were not able to show a protective role of adiponectin in bone mineral density in the obese adolescents in a state of hyperleptinemia (Table 1).…”

“…It is known that insulin induces osteoblast proliferation and collagen production; however, its action is not fully elucidated in patients with signs of insulin resistance (9,(26)(27)(28)(29).…”

The Interrelationships between Abdominal Adiposity, Leptin and Bone Mineral Content in Overweight Latino Children

“…Given the differences in methodology used to measure SAAT and IAAT in our two studies (computed tomography in the previous study versus MRI in the current study), we are unable to make direct comparisons. In these Latino children, we found a positive relationship between IAAT and insulin resistance [10] and a negative relationship between insulin resistance and BMC [11]. We believe that it is physiologically more plausible that the relationship between central adiposity and BMC in Latinos will be more similar to what we previously observed in African-Americans [4] and hypothesize that IAAT and BMC will be inversely correlated in this cohort.…”

Higher Serum Insulin Concentrations Positively Influence the Bone Mineral Density in African American Adolescents

“…This observation should not be taken out of the context that pre-diabetes and type 2 diabetes (T2DM) adversely influences the bone health [6,7]. Prepubertal, obese children with pre-diabetes reportedly have lower bone mass compared to obese, non-diabetic children [7].…”

“…However, recent investigations suggest a potential adverse influence of diabetes and pre-diabetes on the bone [6,7]. It is also widely reported that African Americans (AA) have a greater degree of insulin resistance compared to European Americans (EA) [8], and puberty is a developmental state of increased insulin resistance [9].…”