Johnson, Julie A.

Abstract To gain insights into 1,25-dihydroxyvitamin D3 receptor (VDR) function during fetal bone development, we examined fetal rat tissues from gestational days 13–21 for the presence and distribution of VDR using immuno-histochemistry. Prior to ossification, VDR epitopes were observed in the mesenchyme condensing to form skeletal tissues, on day 13 in the developing vertebral column and limbs, and on day 17 of gestation in developing calvaria. Immunostaining for VDR was seen in proliferating and hypertrophic chondrocytes and in osteoblasts of limb buds and the vertebral column by day 17 of gestation. In calvaria, VDR epitopes were observed in osteoblasts by gestational day 19. VDR immunostaining was also evident in the skin of fetal limbs at all gestational ages examined. We show for the first time that the VDR appears very early in the developing fetal rat skeleton, suggesting that the VDR, in concert with its ligand, 1,25-dihydroxyvitamin D3, may play a role in the differentiation of mesenchymal precursors into bone tissue.

We assessed adverse metabolic effects of atenolol and hydrochlorothiazide among hypertensive patients with and without abdominal obesity using data from a randomized, open-label study of hypertensive patients without evidence of cardiovascular disease or diabetes mellitus. Intervention included randomization to 25 mg of hydrochlorothiazide or 100 mg of atenolol monotherapy followed by their combination. Fasting glucose, insulin, triglycerides, high-density lipoprotein cholesterol, and uric acid levels were measured at baseline and after monotherapy and combination therapy. Outcomes included new occurrence of and predictors for new cases of glucose ≥100 mg/dL (impaired fasting glucose), triglyceride ≥150 mg/dL, high-density lipoprotein ≤40 mg/dL for men or ≤50 mg/dL for women, or new-onset diabetes mellitus according to the presence or absence of abdominal obesity. Abdominal obesity was present in 167 (58%) of 395 patients. Regardless of strategy, in those with abdominal obesity, 20% had impaired fasting glucose at baseline compared with 40% at the end of study ( P <0.0001). Proportion with triglycerides ≥150 mg/dL increased from 33% at baseline to 46% at the end of study ( P <0.01). New-onset diabetes mellitus occurred in 13 patients (6%) with and in 4 patients (2%) without abdominal obesity. Baseline levels of glucose, triglyceride, and high-density lipoprotein predicted adverse outcomes, and predictors for new-onset diabetes mellitus after monotherapy in those with abdominal obesity included hydrochlorothiazide strategy (odds ratio: 46.91 [95% CI: 2.55 to 862.40]), female sex (odds ratio: 31.37 [95% CI: 2.10 to 468.99]), and uric acid (odds ratio: 3.19 [95% CI: 1.35 to 7.52]). Development of adverse metabolic effect, including new-onset diabetes mellitus associated with short-term exposure to hydrochlorothiazide and atenolol was more common in those with abdominal obesity.