Association of Serum Vitamin D with Insulin Resistance and Beta Cell Function in Korean Health Checkup Examinees / 農村醫學 地域保健

OBJECTIVES: This study was conducted to examine the association of serum Vitamin D with insulin resistance and β-cell function in Korean health checkup examinees. METHODS: This study subjects were 374 healthy adults (199 males, 175 females) over the age of 20, who visited a general hospital medical center located in Haenam-gun, Jeollanam-do. To find the association of Vitamin D with HOMA-IR and HOMA-β, the used statistical analysis were ANOVA and ANCOVA. RESULTS: Of the study subjects, the level of serum Vitamin D defined by deficient group, insufficient group and sufficient group was 38.5%, 48.1% and 13.4%, respectively. According to the level of serum Vitamin D, the mean values of HOMA-IR were 1.92±1.08 in sufficient group, 1.99±1.04 in the insufficient group and 2.91±1.05 in deficient group and there were statistically significant different(p<0.001). The mean values of HOMA-β were 84.69±1.07 in sufficient group, 78.41±1.04 in the insufficient group and 80.48±1.04 in deficient group, and there were not significant. As a result of ANCOVA, adjusted mean of HOMA-IR were statistically significant different (p<0.001), but those of HOMA-β were not statistically significant according to the level of serum Vitamin D. CONCLUSIONS: The insufficient level of serum Vitamin D was relatively high in healthy adults who live in rural area, and it was found that HOMA-IR significantly increased when Vitamin D was deficient. To prevent insulin resistance or diabetes, it is necessary to provide sufficient information related to sufficient production of Vitamin D such as Vitamin D supplement, sun exposure, food intake and etc.

Efeitos contrastantes da vitamina D sobre a resposta imune inata e adquirida e seu impacto na recuperação da tuberculose / Contrasting effects of Vitamin D on innate and acquired immune responses and its impact on tuberculosis recover

A vitamina D é um hormônio essencial para o organismo, podendo ser obtida da dieta ou, principalmente, gerada pela pele após exposição à luz solar ultravioleta B. Na sua forma ativa (1,25(oH)2D) ela controla a absorção de cálcio e fósforo do intestino para a corrente sanguínea e participa de diversos processos celulares e fisiológicos. A ligação da 1,25(oH)2D ao receptor da vitamina D (VDr) presente em diversas células, como as células do sistema imunológico, induz a transcrição de genes que podem, por exemplo, modular a resposta imune inata e adquirida. A deficiência de vitamina D ou do VDR é associada a problemas de saúde como desordens esqueléticas, hipertensão, doenças cardiovasculares, diabetes mellitus, dislipidemias, doenças autoimunes e doenças infecciosas. Neste sentido, a suplementação com vitamina D tem sido proposta como uma possível medida preventiva, podendo ser aplicada em muitas patologias, em especial na tuberculose. Principal causa de morte por um único agente infeccioso, a tuberculose é responsável por cerca de 1,3 milhões de óbitos por ano no mundo. Publicações recentes apontam efeitos diversos da vitamina D na resposta imune inata e adquirida. A 1,25(oH)2D3 na presença do interferon (IFN)-γ é capaz de aumentar a atividade bactericida do macrófago contra o M. tuberculosis, aumentando a produção de peptídios antimicrobianos e estimulando a autofagia, favorecendo assim a lise de bacilos localizados em fagossomos. Por outro lado, a vitamina D em linfócitos T mostra efeito tolerogênico que favorece o controle de respostas inflamatórias excessivas. Neste trabalho de revisão são apresentados estudos recentes envolvendo efeitos da vitamina D na resposta imune inata e adquirida. Além disso, considerações sobre deficiência de vitamina D e maior risco de contrair tuberculose, e efeitos contrastantes da suplementação com vitamina D na prevenção e tratamento da TB, são discutidos.

Vitamin D is an essential hormone for the body, and can be obtained from diet or, mainly, generated by the skin after exposure to ultraviolet B sunlight. In its active form (1.25(oH)2D) it controls the absorption of calcium and phosphorus from the intestine into the bloodstream and participates in several cellular and physiological processes. Binding of 1,25(oH)2D to the Vitamin D receptor (VDr) present in several cells, such as cells of the immune system, induces transcription of genes that can, for example, modulate the innate and adaptive immune response. Deficiency of Vitamin D or VDr is associated with health problems such as skeletal disorders, hypertension, cardiovascular disease, diabetes mellitus, dyslipidemias, autoimmune diseases and infectious diseases. In this sense, Vitamin D supplementation has been proposed as a possible preventive measure and can be applied in several pathologies, especially in tuberculosis. main cause of death by a single infectious agent, tuberculosis accounts for about 1.3 million deaths per year worldwide. recent publications point to contrasting functions of Vitamin D in the innate and acquired immune response. 1.25(oH)2D3 in the presence of interferon (IFN)-γ is capable of increasing the bactericidal activity of the macrophage against M. tuberculosis, increasing the production of antimicrobial peptides and stimulating autophagy, thus favoring the lysis of bacilli located in phagosomes. on the other hand, Vitamin D in T lymphocytes shows a tolerogenic effect that favors the control of excessive inflammatory responses. In this review, recent studies involving Vitamin D effects on the innate and acquired immune responses are presented. In addition, considerations about Vitamin D deficiency and increased risk of contracting tuberculosis, and contrasting effects of Vitamin D supplementation on the prevention and treatment of TB, are discussed.

The association of Vitamin D and Parathyroid Hormone with Bone Mineral Density in Korean Postmenopausal Women

BACKGROUND: Osteoporosis results from bone loss due to menopause [estrogen(E) deficiency] and aging. Initial skeletal effect of menopause is accelerated bone resorption with an increase in seurm calcium(Ca) and compensatory but inadequate bone formation. Secretion of parathyroid hormone(PTH) is suppressed at this time. Postmenopausal osteoporosis results in fractures predominantly of trabecular bone, i.e., vertebra. With aging, secondary hyperparathyroidism by low serum Ca and vitamin D deficiency superim poses. Senile osteoporosis produces hip fractures, area of cortical bone. The aim of this study was to- examine the association of vitamin D[25(OH)D] and intact(i) PTH with bone mineral density(BMD) after controlling for suggested confounding factors, and the possibility of low serum vitamin D and high serum iPTH concentration could impact bone loss in Korean postmenopausal women. METHODS: Data from 188 postmenopausal Korean women aged 42 to 69 were analyzed through BMD, serum 25(OH)D, iPTH, Ca, phosphorus(P), alkaline phosphatase(ALP) and clinical characteristics. Factors affecting BMD was determined by Pearson correlation and the relationship between lumbar and femoral neck BMD and vitamin D[25(OH)D] and iPTH was assessed by multiple regression analysis after adjus- ting for suggested confounding factors. RESULTS: Lumbar and femoral neck BMD, serum Ca, P were decresaed and serum iPTH was increased with aging. In Pearson`s correlation, significant contributing factors to lumbar BMD was age, height, weight, menarche, year since menopause(YSM) and ALP. And significant contributing factors to femoral neck BMD was age, height, weight, menarche, YSM and iPTH. No relationship could be demonstrated between serum vitamin D[25(OH)D] and lumbar and femoral neck BMD. How ever, after controlling for potential confounding factors, a correlation was found between vitamin D[25(OH)D] and both of lumbar (p=0.013) and femoral neck BMD(p=0.077). iPTH was inversely related to femoral neck BMD(p=0.004) only in multiple linear regression. CONCLUSION: Serum vitamin D[25(OH)D] was influencing both of vertebral and femoral neck BMD, which suggests a significant role of vitamin D deficiency in the pathogenesis of postmenopausal osteo- porosis. In age related remodeling and loss of bone, increased serum iPTH might have additive role in cortical bone of femur. These findings suggest that vitamin D is very important for optimal bone health and a deleterious effect of increased iPTH on cortical bone loss. Adequate calcium and vitamin D status have to be maintained to prevent osteoporosis in postmenopausal Korean women.