The discovery of effective interventions to prevent or delay disability in older persons is a public health priority. Most likely to benefit from such interventions are frail individuals who are not yet disabled and those with early disability who are at high risk of progression. In spite of this frail older persons have often been excluded from research on the assumption that they would not tolerate testing or benefit from treatment. The Interventions on Frailty Working Group developed recommendations to screen, recruit, evaluate, and retain frail older persons in clinical trials. Specific recommendations are: Eligibility screening should include a multistage process, to quickly exclude those who are too well and those who are too sick. Inclusion criteria should target those most likely to benefit, be meaningful to clinicians, and reflect advancements in the frailty research area. Disability outcome measures should include self-reported, objective, and proxy measures. Strategies to improve retention and compliance and to monitor their effectiveness should be an integral part of the study design. Estimation of cost and sample size should contemplate high dropout rates and interference by competing outcomes. Additional research is needed to refine criteria for screening frail older persons, identify objective measures of disability that are reliable and valid in frail older persons, and improve the informed consent process for high-risk participants, recognizing that research in this subgroup is essential to improving their health outcomes.
Familial male precocious puberty (FMPP) is a gonadotropin-independent disorder that is inherited in an autosomal dominant, male-limited pattern. Affected males generally exhibit signs of puberty by age 4. Testosterone production and Leydig cell hyperplasia occur in the context of prepubertal levels of luteinizing hormone (LH). The LH receptor is a member of the family of G-protein-coupled receptors, and we hypothesized that FMPP might be due to a mutant receptor that is activated in the presence of little or no agonist. A single A-->G base change that results in substitution of glycine for aspartate at position 578 in the sixth transmembrane helix of the LH receptor was found in affected individuals from eight different families. Linkage of the mutation to FMPP was supported by restriction-digest analysis. COS-7 cells expressing the mutant LH receptor exhibited markedly increased cyclic AMP production in the absence of agonist, suggesting that autonomous Leydig cell activity in FMPP is caused by a constitutively activated LH receptor.
Hypoparathyroidism is one of the few remaining hormonal insufficiency states for which replacement therapy is unavailable. Previous short-term controlled trials have shown PTH to be a safe and effective treatment of hypoparathyroidism. In this randomized, parallel group, open-label trial, we compared synthetic human PTH-(1-34) (PTH) with conventional therapy, calcitriol and calcium, over a 3-yr period. Twenty-seven patients with confirmed hypoparathyroidism, aged 18-70 yr, were randomized to either twice daily sc PTH or oral calcitriol and calcium. The primary end points were calcium levels in serum and urine. Secondary end points were creatinine clearance, markers of bone turnover, and bone mineral density. Throughout the 3-yr study period, serum calcium levels were similar in both treatment groups within or just below the normal range. Mean urinary calcium excretion was within the normal range from 1-3 yr in PTH-treated patients, but remained above normal in the calcitriol group. Bone mineral content and bone mineral density showed no significant between-group differences over the 3-yr study period. We conclude that treatment with twice daily sc PTH provides a safe and effective alternative to calcitriol therapy and is able to maintain normal serum calcium levels without hypercalciuria for at least 3 yr in patients with hypoparathyroidism.
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