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Vitamin D is an essential component of bone and mineral metabolism; its deficiency causes growth retardation and skeletal deformities in children and osteomalacia and osteoporosis in adults. Hypovitaminosis D (vitamin D insufficiency or deficiency) is observed not only in adults but also in infants, children, and adolescents. Previous studies suggest that sufficient serum vitamin D levels should be maintained in order to enhance normal calcification of the growth plate and bone mineralization. Moreover, emerging evidence supports an association between 25-hydroxyvitamin D (25[OH]D) levels and immune function, respiratory diseases, obesity, metabolic syndrome, insulin resistance, infection, allergy, cancers, and cardiovascular diseases in pediatric and adolescent populations. The risk factors for vitamin D insufficiency or deficiency in the pediatric population are season (winter), insufficient time spent outdoors, ethnicity (non-white), older age, more advanced stage of puberty, obesity, low milk consumption, low socioeconomic status, and female gender. It is recommended that all infants, children, and adolescents have a minimum daily intake of 400 IU (10 µg) of vitamin D. Since the vitamin D status of the newborn is highly related to maternal vitamin D levels, optimal vitamin D levels in the mother during pregnancy should be maintained. In conclusion, given the important role of vitamin D in childhood health, more time spent in outdoor activity (for sunlight exposure) and vitamin D supplementation may be necessary for optimal health in infants, children, and adolescents.

PurposeTo validate the Dinamap ProCare 200 blood pressure (BP) monitor against a mercury sphygmomanometer in children 7 to 18 years old in accordance with the 2010 International Protocol of European Society of Hypertension (ESH-IP2) and the British Hypertension Society (BHS) protocol.MethodsForty-five children were recruited for the study. A validation procedure was performed following the protocol based on the ESH-IP2 and BHS protocols for children and adolescents. Each subject underwent 7 sequential BP measurements alternatively with a mercury sphygmomanometer and the test device by trained nurses. The results were analyzed according to the validation criteria of ESH-IP2.ResultsThe mean (±SD) difference in the absolute BP values between test device and mercury sphygmomanometer readings was 1.85±1.65 mmHg for systolic BP (SBP) and 4.41±3.53 mmHg for diastolic BP (DBP). These results fulfilled the Association for the Advancement of Medical Instrumentation criterion of a mean±SD below 5±8 mmHg for both SBP and DBP. The percentages of test device-observer mercury sphygmomanometer BP differences within 5, 10, and 15 mmHg were 96%, 100%, and 100% for SBP, and 69%, 92%, and 100% for DBP, respectively, in the part 1 analysis; both SBP and DBP passed the part 1 criteria. In the part 2 analysis, SBP passed the criteria but DBP failed.ConclusionAlthough the Dinamap ProCare 200 BP monitor failed an adapted ESH-IP2, SBP passed. When comparing BP readings measured by oscillometers and mercury sphygmomanometers, one has to consider the differences between them, particularly in DBP, because DBP can be underestimated.

PurposeMatrix metalloproteinases (MMPs) have been implicated in atherosclerosis, and therefore, are considered risk factors for metabolic dysfunction in adults. However, there is little data on circulating levels of MMPs and tissue inhibitors of MMPs (TIMPs) with regard to obesity-related biomarkers in the general adolescent population. In the present study, we determined the associations of MMP-8, MMP-9, and TIMP-1 levels and MMP-8/TIMP-1 and MMP-9/TIMP-1 ratios with obesity-related biomarkers in apparently healthy adolescent boys.MethodsWe measured MMP and TIMP concentrations in plasma samples using the enzyme-linked immunosorbent assay and analyzed their associations with obesity-related biomarkers, such as liver enzymes and lipid profiles, in a sample of 91 Korean boys aged 13-14 years who participated in a general health check-up.ResultsThe mean age of the boys was 13.8±0.3 years; 72 boys were normal weight and 19 were overweight/obese. The Pearson correlation coefficients revealed a significant correlation between MMP-8 and aspartate aminotransferase (r=0.217, P=0.039) and alanine aminotransferase (r=0.250, P=0.017) and between TIMP-1 and aspartate aminotransferase (r=0.267, P=0.011). In a multivariate linear regression analysis, serum alanine aminotransferase was positively associated with the MMP-8 level. There were no significant differences in the MMP-8, MMP-9, and TIMP-1 levels or MMP-8/TIMP-1 and MMP-9/TIMP-1 ratios between control and overweight/obese subjects.ConclusionWe found a significant association between the MMP-8 level and alanine aminotransferase in the apparently healthy adolescent boys. These findings indicate that there may be a pathophysiological mechanism underlying the relationship between MMP-8 and liver enzymes in young adolescents.