Incidence rate of vitamin D deficiency and FGF23 levels in 12- to 13-year-old adolescents in Japan.

INTRODUCTION: The incidence rate of vitamin D deficiency is increasing throughout the world. We measured the incidence rate of vitamin D deficiency and fibroblast growth factor 23 (FGF23) levels in 12- to 13-year-old adolescents in Japan. MATERIALS AND METHODS: A total of 492 adolescents (247 boys and 245 girls) from Japanese community enrolled in this study. 25 hydroxyvitamin D (25(OH)D) was measured with radioimmunoassay. In the subjects with low 25(OH)D levels (≦ 20 ng/ml), intact parathyroid hormone (iPTH), calcium (Ca), phosphorus (P), albumin (Alb), alkaline phosphatase (ALP) and FGF23 were measured. RESULTS: 25(OH)D levels were significantly lower in girls (20.9 ± 3.1 ng/ml) than in boys (22.2 ± 3.3 ng/ml) (p < 0.0001). Fifty-five boys (22.3%) and 83 (33.9%) girls showed vitamin D deficiency (< 20 ng/ml). One-hundred eighty-six (75.3%) boys and 162 (66.1%) girls showed vitamin D insufficiency (≧ 20 ng/ml, < 30 ng/ml). In the subjects whose 25(OH)D levels were ≦ 20 ng/ml, the levels of iPTH, Ca, P, Alb, ALP and FGF23 were 22.3 ± 9.0 pg/ml, 9.5 ± 0.4 mg/dl, 4.7 ± 0.6 mg/dl, 4.6 ± 0.3 g/dl, 920.8 ± 339.3 U/l and 42.6 ± 26.0 pg/ml, respectively. There was a significant negative association between serum 25(OH)D levels and iPTH [r = - 0.290 (p < 0.0001)]. There was no significant association between serum 25(OH)D levels and FGF23. CONCLUSION: We show that 28% of Japanese 12- to 13-year-old early adolescents suffer from vitamin D deficiency. Findings from this study indicate that vitamin D deficiency requires close oversight in public health during adolescence to ensure proper bone health.

Effects of long-term intake of a yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 on mice.

The gut is an extremely complicated ecosystem where micro-organisms, nutrients and host cells interact vigorously. Although the function of the intestine and its barrier system weakens with age, some probiotics can potentially prevent age-related intestinal dysfunction. Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131, which are the constituents of LB81 yogurt, are representative probiotics. However, it is unclear whether their long-term intake has a beneficial influence on systemic function. Here, we examined the gut microbiome, fecal metabolites and gene expression profiles of various organs in mice. Although age-related alterations were apparent in them, long-term LB81 yogurt intake led to an increased Bacteroidetes to Firmicutes ratio and elevated abundance of the bacterial family S24-7 (Bacteroidetes), which is known to be associated with butyrate and propanoate production. According to our fecal metabolite analysis to detect enrichment, long-term LB81 yogurt intake altered the intestinal metabolic pathways associated with propanoate and butanoate in the mice. Gene ontology analysis also revealed that long-term LB81 yogurt intake influenced many physiological functions related to the defense response. The profiles of various genes associated with antimicrobial peptides-, tight junctions-, adherens junctions- and mucus-associated intestinal barrier functions were also drastically altered in the LB81 yogurt-fed mice. Thus, long-term intake of LB81 yogurt has the potential to maintain systemic homeostasis, such as the gut barrier function, by controlling the intestinal microbiome and its metabolites.

Incidence rate and characteristics of symptomatic vitamin D deficiency in children: a nationwide survey in Japan.

There is concern that vitamin D deficiency is prevalent among children in Japan as well as worldwide. We conducted a nationwide epidemiologic survey of symptomatic vitamin D deficiency to observe its incidence rate among Japanese children. A questionnaire inquiring the number of new patients with vitamin D deficiency rickets and/or hypocalcemia for 3 years was sent to 855 randomly selected hospitals with a pediatrics department in Japan. In this survey, we found that 250 children were diagnosed with symptomatic vitamin D deficiency. The estimated number of patients with symptomatic vitamin D deficiency per year was 183 (95% confidence interval (CI): 145-222). The overall annual incidence rate among children under 15 years of age was 1.1 per 100,000 population (95% CI: 0.9-1.4). The second survey has provided detailed information on 89 patients with symptomatic vitamin D deficiency under 5 years of age in hospitals in the current research group. The nationwide and second surveys estimated the overall annual incidence rate of symptomatic vitamin D deficiency in children under 5 years of age to be 3.5 (2.7-4.2) per 100,000 population. The second survey revealed 83% had bowed legs, 88% had exclusive breastfeeding, 49% had a restricted and/or unbalanced diet and 31% had insufficient sun exposure among the 89 patients. This is the first nationwide survey on definitive clinical vitamin D deficiency in children in Japan. Elucidating the frequency and characteristics of symptomatic vitamin D deficiency among children is useful to develop preventative public health strategies.

Association between timing of adiposity rebound and body weight gain during infancy.

OBJECTIVE: To investigate whether increments of weight gain in early infancy are related to the timing of adiposity rebound (AR). STUDY DESIGN: A total of 271 children (147 boys and 124 girls) in 1 community were enrolled in the study. Serial measurements of body mass index were carried out at the ages of 4, 8, and 12 months and 1.5, 2, 3, 4, 5, 6, 7, 8, 9, and 10 years, based on which the age of AR was determined. We also calculated body weight increments in 3 separate periods: birth to 4 months, 4-8 months, and 8-12 months. RESULTS: There was no significant relationship between weight gain in any period of infancy and the age of AR. Weight gain between birth and 4 months was positively correlated only with body mass index at 7 years of age. CONCLUSIONS: We could not find an association between body weight gain during infancy and the timing of AR. This suggests that infantile weight gain is not related to childhood obesity through AR.

A Boy with Reset Osmostat Who Developed Chronic Hyponatremia due to Hypothalamic Injury Caused by a Giant Arachnoid Cyst.

Reset osmostat (RO) is classified as type C among the four subtypes of the syndrome of inappropriate secretion of antidiuretic hormone based on antidiuretic hormone (ADH) secretion. It is characterized by a lower plasma osmolality threshold for ADH excretion when plasma sodium concentration is reduced. We report the case of a boy with RO and a giant arachnoid cyst (AC). The patient had been suspected of having AC since the fetal period, and a giant AC in the prepontine cistern was confirmed by brain magnetic resonance imaging 7 days after birth. During the neonatal period, there were no abnormalities in the general condition or blood tests, and he was discharged from the NICU at the 27 after birth. He was born with a -2 standard deviation short stature and mild mental retardation. When he was 6 years old, he was diagnosed with infectious impetigo and had hyponatremia of 121 mmol/L. Investigations revealed normal adrenal and thyroid functions, plasma hyposmolality, high urinary sodium, and high urinary osmolality. The 5% hypertonic saline and water load tests confirmed that ADH was secreted under low sodium and osmolality conditions, and the ability to concentrate urine and excrete a standard water load; therefore, RO was diagnosed. In addition, an anterior pituitary hormone secretion stimulation test was performed, which confirmed growth hormone secretion deficiency and gonadotropin hyperreactivity. Hyponatremia was untreated, but fluid restriction and salt loading were started at age 12 because of the risk of growth obstacles. The diagnosis of RO is important from the viewpoint of clinical hyponatremia treatment options.

Large molecule protein feeding during the suckling period is required for the development of pancreatic digestive functions in rats.

We examined if large molecule protein feeding during the suckling period is prerequisite for the proper development of pancreatic digestive functions. Most amino acids in breast milk exist as the constituent of large proteins and not as oligopeptides or free amino acids. Accumulating evidence indicates the nutritional importance of large protein feeding for suckling infants; however, evidence on the physiological significance remains small. We thus artificially reared rat pups on a standard rat formula with milk protein or a formula with milk protein hydrolysate from 7 to 21 days of age, and thereafter, fed a standard solid diet until 42 days of age. Pancreas weight and the stock of pancreatic digestive enzymes in the hydrolysate-fed rats were significantly lower than those in the protein-fed rats during and also after the suckling period. Plasma insulin, a stimulator of amylase synthesis, was also significantly low in the hydrolysate-fed rats compared with the protein-fed rats. At 28 days of age, we evaluated the pancreatic secretory ability in response to dietary protein and cholecystokinin (CCK) by means of pancreatic duct cannulation. Pancreatic secretion stimulated by dietary protein in the hydrolysate-fed rats was significantly weaker than that in the protein-fed rats. No significant difference was observed in the increasing rate of pancreatic enzyme secretion in response to CCK between the two groups. These results suggest that the presence of large proteins in breast milk is significant for the development of pancreatic digestive functions and the outcomes could remain even later on in life.