Vitamina D e resistência insulínica em mulheres com síndrome dos ovários policísticos: uma revisão / Vitamin D and insulin resistance in women with polycystic ovarian syndrome: a review

Mulheres que sofrem de síndrome dos ovários policísticos (SOP) estão suscetíveis a diversos tipos de distúrbios metabólicos, em particular, a resistência à insulina (RI), e o status da vitamina D pode contribuir para o desenvolvimento desse quadro. Assim, o objetivo deste estudo foi realizar uma revisão sistemática abordando a associação entre os níveis de vitamina D e RI nas mulheres com SOP. Após a localização de 105 artigos sobre o tema, publicados entre os anos de 2008 e 2018, 17 foram selecionados pelos critérios de inclusão, nos quais se analisou o número de pacientes de cada estudo, o método de verificação dos níveis de vitamina D (por comparação ou suplementação) e os valores do HOMA-IR. Concluiu-se que a associação entre vitamina D e RI na SOP ainda é controversa; contudo, a suplementação com vitamina D apresentou efeitos benéficos, diminuindo ou estabilizando distúrbios metabólicos.(AU)

Women suffering from polycystic ovary syndrome (PCOS) are susceptible to various types of metabolic disorders, in particular, insulin resistance (IR), and vitamin D status may contribute to the development of this condition. Thus, the aim of this study was to perform a systematic review addressing the association between vitamin D and RI levels in women with PCOS. After the publication of 105 articles on the subject, published between 2008 and 2018, 17 were selected by the inclusion criteria - in which the number of patients in each study was analyzed, the method of checking vitamin D levels comparison or supplementation) and HOMA-IR values. It was concluded that the association between vitamin D and IR in PCOS is still controversial; however, vitamin D supplementation showed beneficial effects, decreasing or stabilizing metabolic disorders.(AU)

Prevalence of low bone mass and changes in vitamin D levels in human immunodeficiency virus-infected adults unexposed to antiretrovirals

Abstract INTRODUCTION: The prevalence of low bone mass is 3 times higher in people living with human immunodeficiency virus (PLWH) and using antiretrovirals than in the HIV-unaffected population. Changes in vitamin D levels is one of the factors associated with decreased bone mass. The objective of this study is to evaluate the low bone mass and altered vitamin D levels in PLWH who have not been exposed to antiretrovirals. METHODS: A cross-sectional study was carried out with HIV-infected individuals between the ages of 18 and 55 years immediately prior to the start of antiretroviral therapy in a specialized reference center focusing on infectious and parasitic diseases. Results of clinical examination (patient's weight, height, blood pressure, and clinical history), laboratory tests, and X-ray absorptiometry, were collected. RESULTS: Sixty patients were included, with a mean age of 34 years. Nine (16.7%) patients presented with low bone mass and 4 (7.1%) patients showed low total femur BMD. Analysis revealed that 23.3% and 36.7% of the patients had deficient and insufficient levels of 25-hydroxyvitamin D3, respectively. CONCLUSIONS: Our study population presented with compromised bone health and with low bone mineral density and 25-(OH)-vitamin D levels.

Deficiência da Vitamina D e doenças cardiovasculares / Vitamin D deficiency and cardiovascular diseases

A vitamina D é considerada um hormônio esteroide com amplo espectro de atuação no organismo humano. Sua ação ocorre a partir da ligação do seu metabólito ativo (1α, 25-di-hidroxivitamina D) com seu receptor (VDR) que se encontra presente em todo o organismo, inclusive nas células musculares lisas vasculares e nos cardiomiócitos. Inicialmente, a deficiência de vitamina D havia sido relacionada apenas com alterações no sistema musculoesquelético. Porém, nos últimos anos, pesquisadores têm demonstrado sua relação com diversas patologias pertencentes a outros sistemas, tais como as doenças cardiovasculares. O objetivo deste trabalho foi revisar a fisiopatologia da vitamina D, descrever sua relação com as doenças cardiovasculares com base nas publicações mais recentes e destacar os resultados da suplementação vitamínica na prevenção de tais patologias

Association between hypovitaminosis D and frequency of pulmonary exacerbations in children and adolescents with cystic fibrosis / Associação entre hipovitaminose D e frequência de exacerbações pulmonares em crianças e adolescentes com fibrose cística

Abstract Objective We evaluated the association between vitamin D levels and nutritional status, pulmonary function and pulmonary exacerbations in children and adolescents with cystic fibrosis. Methods 25-hydroxyvitamin D (25(OH)D) levels of 37 children and adolescents were retrospectively evaluated. Pulmonary function, body mass index, height for age, and pulmonary exacerbations episodes were associated with vitamin D levels divided into two groups: sufficient (≥30ng/mL) and hypovitaminosis (<30ng/mL). Results Hypovitaminosis D (25(OH)D <30ng/mL) was observed in 54% of subjects. The mean level of 25(OH)D was 30.53±12.14ng/mL. Pulmonary function and nutritional status were not associated with vitamin D levels. Pulmonary exacerbations over a 2-year period (p=0.007) and the period from measurement up to the end of the follow-up period (p=0.002) were significantly associated with vitamin D levels. Conclusion Hypovitaminosis D was associated with higher rates of pulmonary exacerbations in this sample of children and adolescents with cystic fibrosis. Hypovitaminosis D should be further studied as a marker of disease severity in cystic fibrosis. Further prospective and randomized studies are necessary to investigate causality of this association.

RESUMO Objetivo Avaliar a associação entre níveis de vitamina D e estado nutricional, função pulmonar e exacerbações pulmonares em crianças e adolescentes com fibrose cística. Métodos Os níveis de 25-hidroxivitamina D (25(OH)D) de 37 crianças e adolescentes foram avaliados retrospectivamente. Função pulmonar, índice de massa corporal, altura para a idade, e episódios de exacerbações pulmonares foram associados aos níveis de vitamina D divididos em dois grupos: suficiente (≥30ng/mL) e hipovitaminose (<30ng/mL). Resultados Hipovitaminose D (25(OH)D <30ng/mL) foi observada em 54% dos pacientes. O nível médio de 25(OH)D foi de 30,53±12,14ng/mL. A função pulmonar e o estado nutricional não foram associados aos níveis de vitamina D. As exacerbações pulmonares durante um período de 2 anos (p = 0,007) e do período de medição até o final do período de seguimento (p=0,002) foram significativamente associadas aos níveis de vitamina D. Conclusão A hipovitaminose D esteve associada a maiores taxas de exacerbações pulmonares nesta amostra de crianças e adolescentes com fibrose cística. A hipovitaminose D deve ser mais estudada como marcador da gravidade da doença na fibrose cística. Outros estudos prospectivos e randomizados são necessários para investigar a relação causal desta associação.

Arterial stiffness and 25-hydroxyvitamin D levels in chronic kidney disease patients

Summary Objective: Arterial stiffness refers to arterial wall rigidity, particularly developing in central vessels. Arterial stiffness increases in early stage chronic kidney disease (CKD), and it is a strong predictor of cardiovascular and all cause mortality. Vitamin D has beneficial effects on blood pressure, vascular endothelial function and arterial stiffness. 25-hydroxyvitamin D (25(OH)D) deficiency is quite common worldwide and in the CKD population. We aimed to evaluate the prevalence of 25(OH)D deficiency and its relation with arterial stiffness in CKD. Method: Our study included 101 patients (51 male, 50 female), with stages 3B-5 CKD not on dialysis. A single-cuff arteriograph device (Mobil-O-Graph) was used to evaluate arterial stiffness parameters of pulse wave velocity (PWV) and augmentation index (Alx@75). The patients were divided into two groups: group I vitamin D non-deficient [25(OH)D > 15 ng/mL] and group II vitamin D deficient [25(OH)D ≤ 15 ng/mL]. Results: Overall, the mean 25(OH)D level was 14.1±7.9 ng/mL and 70 patients (69.4%) were vitamin D deficient. The mean Alx@75 value was significantly higher in group II (28.6±10.8% vs. 23.3±13.5%, p=0.038). PWV was higher in group II, but the difference was not significant. Group II exhibited significantly lower serum albumin (p<0.001), hemoglobin (p=0.005), calcium (p=0.041) and estimated glomerular filtration rate (eGFR) (p=0.041), but significantly higher 24-hour proteinuria (p=0.011) and more females (p=0.006). Vitamin D was negatively correlated with Alx@75 augmentation pressure, parathyroid hormone, proteinuria and body mass index, and positively correlated with albumin, hemoglobin, eGFR, calcium and transferrin. 25(OH)D was independently associated with Alx@75 (beta=-0.469, p=0.001) and albumin (beta=0.447, p=0.002). Conclusion: In CKD patients 25(OH)D deficiency was common, particularly in females. Level of 25(OH)D was independently associated with Alx@75.

Evaluation of Quality of life, Physical Activity and Nutritional Profile of Postmenopausal Women with and without Vitamin D Deficiency / Qualidade de vida, atividade física e perfil nutricional de mulheres na pós-menopausa com e sem deficiência de vitamina D

Abstract Introduction Vitamin D deficiency is associated with various diseases. Prevalent in Brazil, it can result from inadequate lifestyle habits. Objective To demonstrate that postmenopausal women with vitamin D deficiency have worse quality of health, expressed as worse quality of life, lower levels of physical activity, and worse nutritional profile. Methods Postmenopausal women answered questionnaires about physical activity and quality of life, provided a 24-hour food record, and had serum vitamin D levels measured. Results Among the more active women, those who perform a daily average of one hour of physical activity had vitamin D levels above 20 ng/mL (76.9%), and those, which expose themselves to sunlight, had vitamin D levels above 30 ng/mL (34.6%). Meanwhile the percentages for the women who are less physically active and less exposed to sunlight were 42.2% and 8.9% respectively. Being more active and more exposed to sunlight resulted in a lower fat percentage. Serum vitamin D levels were not correlated with quality of life. Conclusion Walking and gardening increased serum vitamin D levels and decreased the percentage of body fat. The limitations of the study prevented the impact of 25hidroxyvitamin D on the quality of life and nutritional aspects of the women from being evaluated.

Resumo Introdução A deficiência de vitamina D está associada a diversas doenças. Prevalente no Brasil, pode ser consequência de hábitos de vida inadequados. Objetivo Demonstrar que mulheres na pós-menopausa com hipovitaminose D têm pior qualidade de saúde, expressa por piores qualidade de vida, nível de atividade física e perfil nutricional. Métodos Mulheres na pós-menopausa responderam a questionários sobre atividade física, qualidade de vida, registro alimentar de 24 horas, e tiveram os níveis séricos de vitamina D medidos. Resultados Dentre as mulheres mais ativas, as que praticam em média 1 hora de atividade por dia apresentaram níveis de vitamina D superiores a 20 ng/mL (76,9%), e as que se expõem ao sol apresentaram níveis acima de 30 ng/mL (34,6 %). Já as mulheres menos ativas e menos expostas ao sol apresentaram respectivamente 42,2 % e 8,9%. Ser mais ativa e ter maior exposição solar significou ter menor percentual de gordura. O nível sérico de vitamina D não mostrou relação com a qualidade de vida. Conclusão Caminhada e jardinagem aumentam os níveis séricos de vitamina D e diminuem o percentual de gordura corpórea. As limitações do estudo não permitiram avaliar o impacto da 25-hidróxi-vitamina D na qualidade de vida e nos aspectos nutricionais das mulheres.

Relationship between vitamin D and lung function, physical performance and balance on patients with stage I-III chronic obstructive pulmonary disease / Relação entre vitamina D e função pulmonar, desempenho físico e equilíbrio em pacientes em estágio I a III de doença pulmonar obstrutiva crônica

Summary Objectives: vitamin D is important for muscle function and it affects different aspects of muscle metabolism. This study aim to determine whether serum 25(OH) D levels are related to lung functions, physical performance and balance in patients with chronic obstructive pulmonary disease (COPD). Methods: in 90 patients with COPD and 57 healthy controls lung function tests, physical performance tests (time up and go, gait velocity test, sit-to-stand test, isometric strength, isokinetic strength), static (functional reach test) and dynamic (time up and go) balance tests and the association of 25(OH)D levels with lung functions, physical performance and balance were evaluated. Results: the COPD patients had significantly more deficit in physical function and balance parameters, and in dynamic balance test (p<0.005). Isokinetic knee muscle strength (flexor and extensor) in COPD patients was significantly lower than in the controls (p<0.05); FEV1 (p=0.008), FVC (p=0.02), FEV1/FVC (p=0.04), TLC (p=0.01) were lower in COPD patients with vitamin D deficiency [25(OH) D less than 15ng/mL] than in COPD patients without vitamin D deficiency. Hand grip test (p=0.000) and isokinetic knee muscle strength (flexor and extensor) (p<0.05) were also lower in COPD patients with vitamin D deficiency. Vitamin D deficiency was more pronounced in patients with stage III COPD (p<0.05). Conclusion: patients with COPD had worst physical functioning, poor balance and less muscle strength. Severe disturbed lung and peripheral muscle functions are more pronounced in COPD patients with vitamin D deficiency. .

Resumo Objetivos: a vitamina D é importante para a função muscular e afeta diferentes aspectos do metabolismo muscular. O objetivo é determinar se os níveis séricos de 25 (OH) D estão relacionados com as funções pulmonares, desempenho físico e equilíbrio em pacientes com doença pulmonar obstrutiva crônica (DPOC). Métodos: em 90 pacientes com DPOC e 57 controles saudáveis, testes de espirometria, testes de desempenho (tempo de levantar e ir, teste de velocidade da marcha, teste sitto-stand, força isométrica, força isocinética) e testes de estática (teste de alcance funcional) e dinâmica (tempo de levantar e ir) de equilíbrio foram realizados; e foram avaliados a associação de níveis de 25 (OH) D com as funções pulmonares, desempenho físico e equilíbrio. Resultados: os pacientes com DPOC apresentaram significativamente mais déficit nos parâmetros de função e equilíbrio físico, e no teste de equilíbrio dinâmico (p<0,005). Força muscular isocinética do joelho (flexores e extensores) em pacientes com DPOC foi significativamente menor do que nos controles (p<0,05); VEF1 (p=0,008), CVF (p=0,02), VEF1/CVF (p=0,04), CPT (p=0,01) foram mais baixos em pacientes com DPOC e com deficiência de vitamina D [25 (OH) D menor do que 15 ng/ml] do que em pacientes com DPOC sem deficiência de vitamina D. Os resultados do teste da força de preensão manual (p=0,000) e força muscular isocinética do joelho (flexor e extensor) (p<0,05) também foram menores nos pacientes com DPOC e com deficiência de vitamina D. A deficiência de vitamina D foi mais pronunciada em pacientes em estágio III da DPOC (p<0,05). Conclusão: pacientes com DPOC tiveram pior desempenho físico, falta de equilíbrio e menor força muscular. Perturbações graves das funções pulmonares e musculares periféricas são mais pronunciadas em pacientes com DPOC e com deficiência de vitamina D. .

Niveles de vitamina D en adultos mayores saludables chilenos y su relación con desempeño functional / Vitamin D levels in older healthy Chilean adults and their association with functional performance

Background: People over 60 years old are at risk of Vitamin D deficiency, which can affect functional performance, since this vitamin is involved in muscle function and protein synthesis. Aim: To measure 25OH vitamin D levels in healthy older people from Santiago de Chile, and evaluate their relationship with functional performance. Subjects and Methods: Healthy subjects aged 60 years or more and living in the community were invited to participate. People with chronic diseases, cognitive impairment, physical disability, smokers and those consuming more than three medications per day were excluded. Hand grip and gait speed were measured and a blood sample was obtained to measure 25OH vitamin D by radioimmunoanalysis. Results: One hundred and four participants aged 60 to 98 years (55% females) were studied. Mean vitamin D levels were 17.3 ± 6.1 ng/mL. Females had lower levels than males (15.6 ± 5.8 and 19.2 ± 6.0 ng/mL respectively p < 0.01). Eighty three percent of females and 55.3% of males had values below 20 ng/mL (the cutoff point for deficiency). Only 3.5% of females and 8.5% of males had values of 30 ng/ml or higher. There was a significant correlation between vitamin D levels, gait speed and grip strength (r = 0.32 and 0.34 respectively, p < 0.01), especially in women over 74 years. Conclusions: Vitamin D deficiency is almost universal in healthy adults over 60 years living in Santiago de Chile, especially in women. This deficiency is associated with a deranged functional performance and is a potentially modifiable risk factor for disability.

Vitamina D e diabetes mellitus, suas epidemias e o envelhecimento. O que há de novo? / Vitamin D and diabetes mellitus, their epidemics and the aging. What is new?

O diabetes mellitus do tipo 2, um problema de saúde pública, tem seu diagnóstico e tratamento negligenciados na prática clínica. Embora a abordagem terapêutica tenha avançado nas últimas décadas por meio da melhor compreensão de sua fisiopatologia e do desenvolvimento de fármacos que atuam nas diversas etapas dessa doença, o aumento de novos casos suscita a necessidade do conhecimento de outros alvos terapêuticos e de intervenções clínicas para a prevenção e o tratamento dessa doença. Evidências acumuladas em estudos transversais e longitudinais sugerem uma potencial participação da vitamina D na fisiopatologia do diabetes. Entretanto, os resultados são baseados em estudos clínicos com pequenas amostras, além de não considerar populações específicas, como, por exemplo, mulheres na pós-menopausa, nem tampouco qual o nível de suplementação que deve ser ofertado para uma resposta clínica satisfatória. Com o aumento da expectativa de vida, a detecção precoce, o tratamento e a amenização de quaisquer distúrbios ou doenças que comprometam a qualidade de vida ou afetem os índices de morbimortalidade são essenciais para a melhoria da qualidade de vida. Fazemos uma atualização dessas duas epidemias no contexto de vida da mulher pós-menopausa e das possíveis participações da vitamina D na fisiopatologia do diabetes mellitus do tipo 2.

Type 2 diabetes has been an of public health concern and therefore has its diagnosis and treatment delayed in clinical practice. Although, its treatment has improved in the last decades by better pathophysiology understanding and development of medicines that actin different phases and levels, the increase of new cases of diabetes claim for knowledge about newest terapheutics targets in order to prevent and treat this disease. Accumulatedevidences from crossover and longitudinal studies suggested a potencial participation ofVitamin D in diabetes pathophysiology. However, the results are based on clinical studies with a few sample and do not consider specifical populations like post menopausal womenas did not determine dose of vitamin D that need to be offered. Early diagnosis, treatment and relieve of disorders and diseases that compromise the quality of life are extremely usefull in face to longest aging. We bring up an atualization about how vitamin D could take part on diabetes pathophysiology and some studies results.

Vitamin D and athletic performance: the potential role of muscle

Vitamin D deficiency is a worldwide epidemic, with well known impacts on calcium metabolism and bone health, but increasingly recognized associations with chronic health problems such as bowel and colonic cancer, arthritis, diabetes and cardiovascular disease. In recent years in the Sports Medicine literature, there has been an increased focus on the potential impact that inadequate Vitamin D levels may have on athletic performance. In the early 20[th] Century, athletes and coaches felt that ultraviolet rays had a positive impact on athletic performance, and while remaining limited, evidence is accumulating to support this view. Muscle structure and function is recognised to play a key role in athletic performance, and both cross-sectional and longitudinal studies allude to a functional role for Vitamin D in muscle. The identification of the Vitamin D receptor in muscle tissue provides a direct pathway for Vitamin D to impact upon Skeletal Muscle structure and function. This review focuses on the current understanding of the action of Vitamin D within skeletal muscle tissue, and the potential impact on performance

Vitamin D deficiency and its relationship with bone mineral density among postmenopausal women living in the tropics / Deficiência de vitamina D e sua relação com a densidade mineral óssea em mulheres na pós-menopausa residentes nos trópicos

OBJECTIVE: To determine vitamin D (25OHD) status and its relationship with bone mineral density (BMD) in 93 postmenopausal women. SUBJECTS AND METHODS: Patients were distributed in two groups: Group 1 - 51 to 65 years (n = 45) and Group 2 - 66 to 84 years (n = 48); 25OHD and PTH serum were analyzed and a DXA scan of the lumbar spine (LS) and femoral neck (FN) were taken. RESULTS: Mean ± SD of serum 25OHD levels were 80.6 ± 43.3 nmol/L (Group 1) and 63.7 ± 27.6 nmol/L (Group 2); 24 percent had 25OHD levels < 25 nmol/L and 43.7 percent < 50 nmol/L. The prevalence of vitamin D deficiency at the 62.5 nmol/L cutoff increased significantly with age. Patients with hypovitaminosis D had a lower BMD at the FN (0.738 ± 0.102 vs. 0.793 ± 0.115 g/cm, p = 0.03) and had been postmenopausal for longer (21.0 ± 8.4 vs. 16.2 ± 8.4 years, p = 0.01). CONCLUSION: We found a high prevalence of hypovitaminosis D in postmenopausal women. Age, years elapsed since menopause and low BMD in the FN were associated with deficiency.

OBJETIVO: Determinar o perfil da vitamina D (25OHD) e sua relação com a densidade mineral óssea (DMO) em 93 mulheres na pós-menopausa. SUJEITOS E MÉTODOS: As pacientes foram distribuídas em dois grupos: grupo 1 - 51 a 65 anos (45 pacientes) e 2 - 66 a 84 anos (48 pacientes); foram analisados 25OHD e PTH séricos e realizou-se exame de DXA em coluna lombar (LS) e colo do fêmur (FN). RESULTADOS: As médias ± desvio-padrão (DP) dos níveis de 25OHD foram 80,6 ± 43,3 nmol/L (grupo 1) e 63,7 ± 27,6 nmol/L (grupo 2); 24 por cento tinham 25OHD < 25 nmol/L e 43,7 por cento, < 50 nmol/L. A prevalência de deficiência de 25OHD, considerando 62,5 nmol/L como ponto de corte, aumentou significativamente com a idade. Pacientes com hipovitaminose D tinham uma menor DMO no FN (0,738 ± 0,102 vs. 0,793 ± 0,115 g/cm², p = 0,03) e maior tempo de pós-menopausa (21,0 ± 8,4 vs. 16,2 ± 8,4 anos, p = 0,01). CONCLUSÃO: Encontrou-se alta prevalência de hipovitaminose D em mulheres na pós-menopausa. Idade, anos desde a menopausa e baixa DMO no FN estavam associados à deficiência.

Níveis baixos de 25-hidroxivitamina D (25OHD) em pacientes com doença inflamatória intestinal e sua correlação com a densidade mineral óssea / Low levels of 25-hydroxyvitamin D (25OHD) in patients with inflammatory bowel disease and its correlation with bone mineral density

INTRODUÇÃO: Pacientes com doenças inflamatórias intestinais (DII) estão propensos a apresentar níveis baixos de vitamina D (25OHD) e densidade mineral óssea (DMO) diminuída. OBJETIVO: Verificar o nível de 25OHD em jovens com DII submetidos à avaliação clínica, dosagens bioquímicas rotineiras e medida da DMO de coluna lombar e fêmur, comparando-os com controles saudáveis. RESULTADOS: 39 pacientes com doença de Crohn (DC) (p = 0, 003) e 37 com retocolite ulcerativa inespecífica (RCUI) (p < 0,001) apresentaram níveis mais baixos de 25OHD comparados aos controles, 48,5 por cento dos pacientes com RCUI tinham deficiência de 25OHD. A DMO em coluna lombar foi mais baixa nos doentes (DC p = 0,001; RCUI p = 0,008). A 25OHD correlacionou-se significativamente com a DMO do fêmur total (r = 0,391; p = 0,027) e colo do fêmur (r = 0,384; p = 0,03) na DC. CONCLUSÃO: Foram encontrados níveis baixos de 25OHD e DMO em jovens com DII, sugerindo papel importante desta deficiência na patogênese da doença óssea desses pacientes.

Patients with inflammatory bowel disease (IBD) are at risk of having vitamin D deficiency (25-OHD) and low bone mineral density (BMD). OBJECTIVES: To measure 25OHD in a young group of IBD patients submitted to a clinical evaluation, routine biochemistry and BMD measurement (lumbar spine and proximal femur). RESULTS: 39 Crohn disease (CD) and 37 ulcerative colitis (UC) patients had lower serum levels of 25OHD compared to the control group (CD p = 0,003; UC p < 0,001), and 48.5 percent of the UC patients were 25OHD deficient. Lumbar spine BMD was lower in patients than controls (CD p = 0,001; UC p = 0,008). In CD patients, serum levels of 25OHD were significantly correlated with total femur (r = 0,391; p = 0,027) and femoral neck (r = 0,384; p = 0,03) BMD. CONCLUSION: It was found lower levels of 25OHD and BMD in young IBD patients compared to normal controls, suggesting an important role of 25OHD deficiency in the pathogenesis of the IBD bone disease.

Correlation between serum vitamin D (25(OH)D) concentration and quadriceps femoris muscle strength in Indonesian elderly women living in three nursing homes.

AIM: to investigate the correlation between serum vitamin D (25(OH)D) concentration and quadriceps femoris muscle strength. METHODS: this was a cross-sectional correlative study, conducted at three nursing homes in Jakarta and one nursing home in Bekasi in January 2005. The subjects were women aged 60 years or above. Those selected study subjects underwent quadriceps femoris muscle strength examination with Cybex dynamometer with 150 degrees/second speed, twice (three repetitions with 30 second rest time). The 25 (OH)D concentration was measured by ELISA. RESULTS: out of 67 subjects who met the required criteria for this study, five subjects withdrew from the study during muscle strength examination. The mean age was 71.1 (SD 7.2) years old while the mean serum vitamin D concentration was 68.2 (SD 21.6) nmol/l. Vitamin D deficiency (<or= 50 nmol/l) was found in 22.6% of subjects. It was also found that the median (minimum-maximum) quadriceps femoris muscle strength was 40.00 (11-116) N.m. Approximately 82.3% of the subjects were of generalized muscle weakness. Correlation was found between serum 25 (OH)D concentration and quadriceps femoris muscle strength (r = 0.327; P = 0.009). CONCLUSION: this study reveals that serum 25 (OH) D concentrations in Indonesian elderly women is correlated with quadriceps femoris muscle strength. The proportion of elderly women with muscle weakness is higher than the normal ones. The group with older age shows higher proportion of muscle weakness. Most subjects have normal serum vitamin D concentration.

Papel da vitamina D na função neuro-muscular / Role of vitamin D in the neuro-muscular function

A vitamina D, através de suas ações no intestino, rim, osso e glândulas paratiróides, é um hormônio fundamental para a homeostase do cálcio e para o desenvolvimento de um esqueleto saudável. Além disso, receptores deste hormônio podem ser encontrados em quase todos os tecidos do organismo e outras ações não relacionadas ao metabolismo mineral têm sido imputadas a ele. Na célula muscular esquelética, a vitamina D atua através do mecanismo clássico de ligação a um receptor nuclear e também através da ligação a um receptor de membrana, realizando ações que envolvem o transporte de cálcio, a síntese protéica e a velocidade de contração muscular. Clinicamente, a deficiência de vitamina D, que é bastante comum em idosos, inclusive em nosso país, tem sido relacionada a um aumento da incidência de quedas, a uma diminuição da força muscular e a uma deterioração do equilíbrio, avaliada pela oscilação do corpo na postura ereta. Por outro lado, tem sido demonstrado que a suplementação associada de cálcio e vitamina D em idosos deficientes contribui para melhoria destes aspectos da função neuro-muscular. Nesta revisão, serão discutidos os mecanismos conhecidos envolvidos na associação entre vitamina D e função neuro-muscular, e também a suplementação de vitamina D e cálcio na prevenção de fraturas osteoporóticas não-vertebrais sob a perspectiva dos efeitos neuro-musculares.

Effect of vitamin D deficiency on electrocardiogram of rats.

Electrocardiograms (ECGs) were studied in rats fed vitamin D deficient diet for 12 weeks. The results indicated significant shortening of QT interval of ECG. Other intervals were normal when compared with age matched control rats. Heart/body weight ratio was significantly increased in vitamin D deficient group, which is an index of hypertrophy, with increased collagen fiber in the histology of the myocardium, inspite of normal serum calcium level. The results suggested a direct role of vitamin D in the regulation of cardiac functions.