The concurrent validity between leptin, BMI and skin folds during pregnancy and the year after.

BACKGROUND: From a public health perspective it is important to know which of the currently used methods to estimate changes in maternal body fat during pregnancy and the year thereafter is the most adequate. OBJECTIVES: To evaluate the concurrent validity between leptin and surrogates of fat measures: body mass index (BMI) and the sum of four skin folds. DESIGN: Data from the New Life(style) intervention study were analysed as a cohort study. SETTING: Midwife practices in The Netherlands. POPULATION: Healthy pregnant nulliparous women. METHODS: Anthropometric measurements were done and blood was collected at 15, 25 and 35 weeks of pregnancy and at 6, 26 and 52 weeks after delivery. Data were used if at least 4 out of the 6 measurements were available, leaving 87 women in the analyses. Spearman's correlation coefficients between leptin and BMI and between leptin and the sum of skin folds were calculated for each time point and for the changes between the time points. RESULTS: Correlations between leptin and BMI varied from 0.69 to 0.81. Correlations between leptin and the sum of skin folds were comparable, varying between 0.65 and 0.81.Correlations between changes in leptin and changes in BMI and the sum of skin folds, respectively, were much lower compared with cross-sectional correlations. CONCLUSION: Because of the high correlation among the three methods and because of the overlapping intervals, all methods seem to be equally adequate to estimate changes in maternal body fat during pregnancy and the year thereafter.

Concurrent validity of a weight-bearing activity questionnaire in prepubertal and pubertal girls and boys.

OBJECTIVE: The purpose of this study was to evaluate the current validity of an interviewer-administered physical activity questionnaire against measurement of physical activity from vertical body accelerometer movements in prepubertal and pubertal children. METHODS: The Weight Bearing Activity Questionnaire for Kids (WBAQK) is an interviewer-administered questionnaire with a recall over 7 days and developed to assess weight-bearing activity in pre-pubertal and pubertal children. The Caltrac(TM) accelerometer was worn for 4-5 days (including 1 weekend day). Thirty-seven schoolgirls and 35 schoolboys participated, with a mean age of 11.2 0.3 years and 12.1 0.2 years, respectively. RESULTS: Weight-Bearing Score (WBS) and Metabolic Score (MS) derived from the WBAQK were significantly and positively related to the score of the Caltrac(TM). Weight-Bearing Score showed higher correlations in both boys (0.59) and girls (0.53) and slightly better compared to MS (0.54 and 0.35). The classification of boys and girls into high and low activity groups resulted also in a better agreement of WBS (71-72%) than of MS (60-67%) with Caltrac(TM). CONCLUSIONS: We conclude that the amount of weight-bearing activity can be estimated with the interviewer-administered WBAQK in boys and girls between 8 and 14 years of age.

Growth hormone treatment in Turner syndrome accelerates growth and skeletal maturation. Dutch Growth Hormone Working Group.

Sixteen girls with Turner syndrome (TS) were treated for 4 years with biosynthetic growth hormone (GH). The dosage was 4 IU/m2 body surface s.c. per day over the first 3 years. In the 4th year the dosage was increased to 6 IU/m2 per day in the 6 girls with a poor height increment and in 1 girl oxandrolone was added. Ethinyl oestradiol was added after the age of 13. Mean (SD) growth velocities were 3.4 (0.9), 7.2 (1.7), 5.3 (1.3), 4.3 (2.0) and 3.6 (1.5) cm/year before and in the 1st, 2nd, 3rd and 4th year of treatment. Skeletal maturation advanced faster than usual in Turner patients especially in the younger children. Although the mean height prediction increased by 5.6 cm and 11 of the 16 girls have now exceeded their predicted height, the height of the 4 girls who stopped GH treatment exceeded the predicted adult height by only 0 to 3.4 cm.

A girl treated with growth hormone presenting with neuromyopathy as first sign of acute lymphoblastic leukemia.

An 11-year-old girl being treated with DNA-recombinant growth hormone therapy presented with proximal limb weakness. Laboratory studies were negative. A few months later she presented with acute lymphoblastic leukemia (ALL). A diagnosis of carcinomatous neuromyopathy was made. After successful treatment of the leukemia the symptoms subsided and did not recur.

Intra- and inter-observer variability in the assessment of testicular descent.

Measurements of the distance between the testis and the pubic tubercle have been used to differentiate retractile testes from "real" cryptorchidism and to measure the effect of therapy. The intra- and inter-observer variation of these measurements was determined in 21 boys with incompletely descended testes treated with placebo. Patients were investigated in supine and squatting position, before and during moderate caudal traction. In squatting position the average distance is 20 mm greater than in supine position. The intra-observer SD is approximately 10 mm. It is doubtful if quantitative measurements can be used to define retractile testes. The wide prediction intervals should be taken into account in interpreting results of therapy.