[Bone mineralization in children and adolescents with type 1 diabetes]. / Mineralização óssea em crianças e adolescentes com diabetes melito tipo 1.

OBJECTIVE: To evaluate the occurrence of osteopenia and the prognostic factors of bone mass in a pediatric group with type 1 diabetes. METHODS: The following parameters were analyzed in a group of 23 patients with type 1 diabetes aged 10.9 -/+ 2.9 years: bone mineral density, serum C peptide, glycosylated hemoglobin, serum calcium, serum alkaline phosphatase, serum phosphorus and calciuria. Clinical variables included age, weight, height, body mass index, pubertal stage, insulin doses, duration of diabetes and calcium intake. Bone mineral density was evaluated in the lumbar spine and the results were expressed in deviation standard score by age and sex. Calcium intake was calculated based on feeding report, body mass index was calculated using the Quetelet formula and pubertal stage was defined according to the Tanner-Whitehouse criteria. Simple linear regression was used to analyze correlations between variables and the Mann-Whitney U test was used to compare groups. RESULTS: Average bone mineral density was normal (-0.75 -/+ 1.01 SD). However we verified that 39.1% of the patients had osteopenia. When comparing data of osteopenic patients (n = 9) to non-osteopenic patients (n =1 4), we observed that C peptide of osteopenic group was higher than that of non-osteopenic group (0.56 -/+ 0.18 vs 0.29 -/+ 0.20; p < 0.05). Body mass index and C peptide correlated with bone mineral density. Duration of diabetes was inversely correlated with C peptide (p < 0.01) and directly correlated with insulin doses (p < 0.01). CONCLUSION: Osteopenia occurred in 39.1% of the patients with type 1 diabetes. The presence of osteopenia was related to higher levels of C peptide.

Mineralização óssea em crianças e adolescentes com diabetes melito tipo 1 / Bone mineralization in children and adolescents with type 1 diabetes

Objetivo: estudar a ocorrência de redução da massa óssea e seus fatores prognósticos em um grupo de pacientes pediátricos com diabetes melito tipo l.Métodos: estudamos 23 pacientes portadores de diabetes melito tipo 1, com idade média de 10,9 2,9 anos. Analisou-se a massaóssea, ingestão de cálcio, IMC, peso, estatura, estágio puberal, dose de insulina, duração do diabetes, cálcio, fósforo, fosfatase alcalina, peptídeo C e hemoglobina glicosilada. A massa óssea foi avaliada em coluna lombar, através de densitometria óssea, e expressa em desvio padrão da média para idade e sexo (DP). A ingestão de cálcio foi calculada através de recordatório alimentar, o IMC, calculado de acordo com a fórmula de Quetelet, e o estágio puberal definido segundo os critérios de Tanner- Whitehouse. Utilizou-se a regressão linear simples para o estudo das relações entre as variáveis e a uMann-Whitney na comparação entre grupos.Resultados: observamos que a média da densidade mineral óssea(DMQ) foi normal (-0, 75 1,01 DP). No entanto, verificamos que 39,1por cento dos pacientes apresentavam osteopenia. Ao comparar os dados dos pacientes osteopênicos (n=9) com os não osteopêrticos(n=14), observamos que o peptídeo C do grupo osteopênico foi superior (0,56 0,18 vs. 0,29 0,20, p<0,05). O IMC e o peptídeo C correlacionaram-se com a DMO. A duração do diabetes correlacionou-se negativamente com o peptídeo C (p<0,01) e positivamente com a dose de insulina (p<0,01).Conclusão: no grupo de diabéticos estudado, encontramos uma freqüência de osteopenia de 39,1 por cento. A presença de osteopenia esteve relacionada a níveis séricos superiores de peptídeo C

Clinical and biochemical determinants of bone metabolism and bone mass in adolescent female patients with anorexia nervosa.

Among pathologies prevalent in western societies, anorexia nervosa has increased over the last decade. Its effects on bone mass need to be defined, and prognostic factors, either clinical or biochemical, could aid clinicians in individual patient management. To determine which clinical and/or biochemical parameters could be related to bone mass status in adolescent female anorexia nervosa patients, 73 female patients were classified according to different stages of their illness and studied in terms of clinical and biochemical parameters and bone densitometric mineral content at lumbar spine. Patients (age 17.2 +/- 1.7 y, mean +/- SD) with Tanner pubertal stage 5, regular menstruation for more than 3 mo before the onset of secondary amenorrhea, and diagnosed with anorexia nervosa were consecutively studied and classified in three clinical situations: I) active phase (34 patients): undernourished and amenorrheic; II) weight recovered but still amenorrheic (20 patients); III) fully recovered (19 patients). Clinical data were recorded at the time of bone density measurement, concomitant with blood sample extraction for study of IGF-I, IGF-binding protein 3 (IGFBP-3), IGFBP-1, estradiol, sex hormone-binding globulin, dehydroepiandrosterone sulfate, prealbumin, amino-terminal propeptide of procollagen III, osteocalcin, bone alkaline phosphatase, carboxy-terminal propeptide of procollagen I, amino-terminal propeptide of procollagen I, carboxy-terminal telopeptide of collagen I, 25-OH-vitamin D, 1,25(OH)(2)-vitamin D, and parathormone. In addition, a 24-h urine collection was made for cortisol, GH, deoxypyridinoline, amino-terminal telopeptide of collagen I, and calcium and creatinine content analysis. IGF-I, estradiol, and biochemical bone formation markers were higher and IGFBP-1, sex hormone-binding globulin, and biochemical bone resorption markers were lower in the weight-recovered stages (stages II and III) compared with the active phase (stage I). Bone formation markers correlated positively with body mass index SD score and IGF-I, whereas bone resorption markers correlated negatively with body mass index SD score and estradiol. Although no statistically significant differences regarding lumbar spine bone mineral density SD score values were recorded among the three stages of the illness, the proportion of osteopenic patients was clearly lower among stage III patients. The actual bone mineral density was inversely related to the duration of amenorrhea and directly related to duration of postmenarcheal menses before amenorrhea. In addition, a subset of osteopenic patients (five of 19) in the fully clinically recovered group with accelerated bone turnover was identified. Normal circulating estrogen level exposure time predicts actual bone mineral density at lumbar spine in young adolescent anorexia nervosa patients. In addition to psychiatric and nutritional interventions, estrogen-deprivation periods must be shortened to less than 20 mo. Patients remaining osteopenic at full clinical recovery require additional follow-up studies.