Simmons, Patricia S.

1. To investigate whether there is a nyctohemeral rhythm in bone turnover, we measured serum bone Gla-protein (osteocalcin, an index of osteoblast activity) concentration every 2 h and urinary deoxypyridinoline (a marker of bone collagen resorption) excretion for 8 h periods in 10 pubertal girls (aged 10–14 years), 15 premenopausal women (aged 20–49 years) and 17 postmenopausal women (aged 50–75 years). 2. The serum concentration of bone Gla-protein and the urinary excretion of deoxypyridinoline were five times higher in the pubertal girls than in the premenopausal women. The urinary excretion of deoxypyridinoline in the postmenopausal women was twice that in the premenopausal women. 3. There was a nyctohemeral pattern in all age groups with mean night-time increases of 28% (P<0.001) in the urinary excretion of deoxypyridinoline and of 5% (P<0.001) in the serum bone Gla-protein concentration. 4. There also were nyctohemeral patterns in the urinary excretion of calcium (P<0.02), sodium (P<0.001) and potassium (P<0.001), with decreases at night. There was a negative correlation between the night-time changes in the urinary excretion of deoxypyridinoline and calcium, especially in adult women (P<0.01). 5. The serum level of parathyroid hormone increased with age, but this effect was only observed at night (01.00 to 07.00 hours). There was a nyctohemeral rhythm of the serum intact parathyroid hormone level at all ages, with a peak in the afternoon and night. 6. Thus, at night, there is a large increase in bone resorption and a small increase in osteoblastic activity, representing a nyctohemeral rhythm of bone turnover. Although the amplitudes of bone formation and bone resorption are greater during growth, the pattern of nyctohemeral changes present during growth continues up to the age of 75 years.

Objective. To determine parents' knowledge and attitudes of medicolegal issues affecting adolescent medical care. Design. An anonymous, mailed survey with 16 questions concerning Minnesota consent and confidentiality laws that affect adolescents' medical care. Setting. A community of >70 000 in rural, southeastern Minnesota. Participants. Parents of 600 randomly selected 7th- through 12th-grade public school students. Results. Two hundred eighty-eight (48%) parents returned the surveys. Parents achieved a median score of 18.8% (range, 0%–93.8%) correct on a test of knowledge. Opinion was a median of +0.3 on a scale where −1 signified “a bad law,” 0 signified “neither a good nor bad law,” and +1 signified “a good law.” Four questions, however, generated a more intense response. Seventy-seven percent of parents reported that, as a whole, the laws in the survey had no effect on them and/or their children. Conclusions. These results suggest that parents are not knowledgeable of Minnesota laws that affect adolescent medical care. Overall opinion of these laws was mildly positive, with notable exceptions. Parents also lack a sense of impact of laws affecting adolescent medical care. Lack of knowledge and the presence of certain attitudes allow for identification of issues that clinicians should address by incorporating medicolegal education into the care of adolescents and their families. These results are especially timely in light of the Parental Rights and Responsibilities Act under consideration in Congress, which would provide parents greater authority over their children's medical care.