To study the relationships between serum vitamin D levels and plasma glucose or lipid levels in children and adolescents.
We conducted a retrospective record review of pediatric outpatients (age, 2-18 years) with simultaneous measurement of 25-hydroxyvitamin D (25[OH] D) and fasting plasma glucose (n = 302) or 25(OH) D and a lipid panel (n = 177). Pearson correlation coefficient was used to estimate the correlation between 25(OH) D and logarithmic transformed plasma glucose or lipid levels. Plasma glucose and lipid levels were compared in subjects with 25(OH) D concentrations greater or less than 30 ng/mL.
25(OH) D levels were inversely correlated with fasting plasma glucose levels (r = -0.20, P < .001). Lower 25(OH) D levels were also associated with lower serum high-density lipoprotein cholesterol (HDL) concentrations (r = 0.41; P < or = .001). The relationship between 25(OH) D levels and fasting glucose and HDL levels did not vary significantly with sex, age, body mass index z-score, or season. Children who were vitamin D insufficient (25[OH] D < or =30 ng/mL) had higher fasting plasma glucose (P = .002) and lower HDL levels (P < .001) than children who were vitamin D sufficient (25[OH] D >30 ng/mL).
Low 25(OH) D levels in children and adolescents are associated with higher plasma glucose and lower HDL concentrations.
"Concerning young populations, several studies have shown that vitamin D levels are lower in the presence of overweight/obesity, and that low levels of 25(OH)D could influence the risk of developing metabolic disorders and cardiovascular disease in pediatric and adolescent populations [4-6]. Obesity associated-vitamin D insufficiency is likely caused by deposition of skin and dietary vitamin D3 in body fat compartments, resulting in decreased bioavailability . "
[Show abstract][Hide abstract] ABSTRACT: Vitamin D deficiency has been associated with a multitude of disorders including diabetes, defective insulin secretion as well as rickets and poor bone health. Vitamin D is also a concern during childhood and adolescence and has been reported in girls from South Brazil. We determined the prevalence of vitamin D deficiency in girls from South Brazil and investigated whether the genotypic distribution of the BsmI, ApaI and TaqI polymorphisms of the VDR gene and their haplotypes were associated with vitamin D levels.
Cross-sectional study including 234 apparently healthy girls aged 7 to 18 years. Height and weight were measured for calculation of body mass index (BMI) percentiles for age. Plasma levels of 25-hydroxyvitamin D [25(OH)D] were assessed. Participants were genotyped for ApaI (rs7975232), TaqI (rs731236), and BsmI (rs1544410) SNPs.
The median and interquartile range (25-75%) of BMI percentile was 62.0 (33.3 - 84.9). The frequency of overweight/obesity was 24.9%. Circulating levels of 25(OH)D (≥ 30 ng/mL) were adequate in 9.4%; insufficient in 54.3% (20-29 ng/mL); and deficient in 36.3% (< 20 ng/mL). Genotype frequencies were GG = 47.0%, GA = 41.5%, and AA = 11.5% for BsmI; GG = 16.7%, GT = 52.6%, and TT = 30.8% for ApaI; TT = 46.2%, TC = 44.9% and CC = 9.0% for TaqI. Genotypes with no gene variance (ancestral wild genotype) of BsmI (GG vs. GA + AA, two-tailed Student's t-test p < 0.001), ApaI (GG vs. GT + TT, two-tailed Student's t-test p = 0.031) and TaqI (TT vs. TC + CC, two-tailed Student's t-test p = 0.005) SNPs and the GGT haplotype (two-tailed Student's t-test p = 0.036) were significantly associated with lower 25(OH)D levels.
25-hydroxyvitamin D deficiency and insufficiency were highly prevalent in this sample. The BsmI, ApaI and TaqI wild variants of the VDR gene, as well as the GGT haplotype, were associated with lower vitamin D levels, suggesting that VDR gene polymorphisms could be linked to higher susceptibility to vitamin D deficiency in a sub-population of children and adolescents.
"On the other hand, the number of studies on the relation of 25(OH)D levels with daily insulin requirement and metabolic control in children is limited. Johnson et al (22) found an inversely proportional correlation between fasting blood sugar level and 25(OH)D in pediatric outpatients. Svoren et al (11) and Tunc et al (19) showed that low serum 25(OH)D levels were associated with poor metabolic control in T1D patients. "
[Show abstract][Hide abstract] ABSTRACT: To investigate the frequency and effects of vitamin D deficiency in children with type 1 diabetes (T1D) in a region which is known to have a high rate of vitamin D deficiency among adolescents.
In this prospective cross-sectional study, 120 children and adolescents with T1D (55 girls and 65 boys) aged 3-20 years were evaluated. Serum 25-hydroxyvitamin D [25(OH)D], parathormone (PTH), and alkaline phosphatase (ALP) levels were measured. Hemoglobin A1c levels and daily insulin requirement were also evaluated. Classification of vitamin D status was made according to the American Academy of Pediatrics (AAP)/LWEPS's recommendations. The patients were divided into 2 groups according to their vitamin D status and also according to the season of the year in which 25(OH)D sampling was done.
Serum 25(OH)D levels revealed vitamin D deficiency or insufficiency in 38% of the patients. Higher PTH levels were found in the patient group whose mean 25(OH)D level was < 20 ng/mL as compared to the group whose mean 25(OH)D level was > 20 ng/mL (p < 0.05). Only 11% of patients had secondary hyperparathyroidism. The 25(OH)D levels of patients whose serum samples were taken in summer and spring months were significantly different (p < 0.05). There were no significant correlations between 25(OH)D level and daily insulin dose.
Although we could not show a significant association between vitamin D deficiency and metabolic parameters, the frequency of vitamin D deficiency in T1D children is substantial. Vitamin D status should be assessed also in patients who do not have signs of rickets.
Journal of Clinical Research in Pediatric Endocrinology 12/2011; 3(4):179-83. DOI:10.4274/jcrpe.430
[Show abstract][Hide abstract] ABSTRACT: The authors describe MFMS (mechanical finger modeling system), a
computer model that was built to simulate a generic human finger. The
MFMS permits the study of relationships among bone, muscle, and tendon,
in addition to geometric and static properties of the finger. A specific
application addressed is the determination of the existence of
one-to-many mappings between tendon lengths and finger joint angles. For
a given set of tendon lengths determined by the application of muscle
forces from the extrinsic muscles of the finger, there exists more than
one set of joint angles that the finger can assume. This research shows
that for an anthromorphically motivated mechanical finger model there
can be more than one finger position with the exact same tendon lengths.
This can be carried over to the human finger model and is a key concept
for the understanding of joint position perception by the finger.
Implications for robot hand control are considered
Intelligent Control, 1992., Proceedings of the 1992 IEEE International Symposium on; 09/1992
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