Testosterone Levels Following Decreases in Serum Osteocalcin

Recent preclinical studies suggest that osteoblasts are able to induce testosterone production by the testis, a process mediated by osteocalcin. Bisphosphonates substantially reduce osteocalcin levels. If osteocalcin is an important regulator of testosterone levels in adult men, it would be expected that the substantial reductions in osteocalcin induced by zoledronate would impact negatively on testosterone levels. Previously, we carried out a 2-year randomized, controlled trial of annual 4 mg zoledronate in 43 HIV-infected men. To explore the relationship between osteocalcin and testosterone further, we measured serum testosterone at baseline, 3 months, and 2 years; luteinizing hormone at 3 months and 2 years; and total osteocalcin at 2 years in 28 trial participants with available blood samples. At 2 years, total osteocalcin was 39 % lower in the zoledronate group than the placebo group (zoledronate mean 10.1 [SD 3.0] μg/L, placebo 16.5 [SD 4.9] μg/L, P = 0.003). Despite these substantial differences in osteocalcin levels, testosterone levels did not change over time in either group and there were no between-group differences over time, P = 0.4 (mean change at 2 years [adjusted for baseline levels] in zoledronate group ?0.4 nmol/L, 95 % CI ?2.5 to 1.6; placebo group 0.4 nmol/L, 95 % CI ?1.6 to 2.5). Luteinizing hormone was within the normal range and did not differ between the groups at either 3 months or 2 years. Thus, the absence of a change in testosterone despite a substantial reduction in osteocalcin following zoledronate treatment argues against a biologically significant role for osteocalcin in the regulation of testosterone in adult men. This provides reassurance that men receiving potent antiresorptive drugs are not at risk of iatrogenic hypogonadism.     

Inaccuracy of high-performance liquid chromatography estimation of haemoglobin F in the presence of increased haemoglobin A1c

Increasingly high-performance liquid chromatography is being used for identification and quantification of normal and variant haemoglobins. In many laboratories, the Beta Thal Short programme of the Bio-Rad Variant II instrument is used for this purpose. We noted that a factitious elevation of haemoglobin F was sometimes observed in diabetic patients and therefore carried out a systematic study of this phenomenon. We found discrepant results in 41% of samples from diabetic patients but in no normal volunteers. This factitious elevation could be predicted from a retention time for haemoglobin F of more than 1.15 min, the normal retention time being 1.08-1.15 min. Haemoglobinopathy laboratories need to be alert to the possibility of this erroneous result.     

The family context of an intervention to prevent type 2 diabetes in high-risk teens

PURPOSE: This research describes the family context of eating and mealtime patterns in young adolescents at high risk for type 2 diabetes and the implications for preventing this disease. METHODS: Ten families, each consisting of a child and one parent, participated in individual, semistructured interviews that focused on family eating patterns. Topics included meal schedules, food preparation, family eating patterns, school eating patterns, and perception of the child's weight. Interviews were audiotaped, transcribed verbatim, and analyzed using focused summaries and thematic analysis methods. RESULTS: Four main themes were identified: child and family eating patterns, perspectives on obesity, perspectives on weight control, and health concerns. Family eating patterns were often inconsistent, and few healthy eating models were available at home or school. Obesity was not always seen as a negative factor, particularly by the youth. Weight-control efforts were sporadic, typically unsuccessful, and consisted primarily of intermittent increases in physical activity. Parents did not actively participate in their child's weight-control efforts. CONCLUSIONS: Effective interventions for obesity and prevention of type 2 diabetes in youth should include parents in both cognitive and behavioral strategies.