Regional variation and determinants of vitamin D status in sunshine-abundant Thailand

<p>Abstract</p> <p>Background</p> <p>Vitamin D insufficiency is highly prevalent. Most of the studies concerning vitamin D status were generated from countries situated at temperate latitudes. It is less clear what the extent of vitamin D insufficiency is in countries situated in the tropics and how geographical regions within country would affect vitamin D status. In the present study, we investigated vitamin D status in Thais according to geographical regions and other risk factors.</p> <p>Methods</p> <p>Subjects consisted of 2,641 adults, aged 15 - 98 years, randomly selected from the Thai 4th National Health Examination Survey (2008-9) cohort. Serum 25 hydroxyvitamin D were measured by liquid chromatography/tandem mass spectrometry. Data were expressed as mean ± SE.</p> <p>Results</p> <p>Subjects residing in Bangkok, the capital city of Thailand, had lower 25(OH)D levels than other parts of the country (Bangkok, central, northern, northeastern and southern regions: 64.8 ± 0.7, 79.5 ± 1.1, 81.7 ± 1.2, 82.2 ± 0.8 and 78.3 ± 1.3 nmol/L, respectively; <it>p </it>< 0.001). Within each region, except for the northeastern part of the country, subjects living inside municipal areas had lower circulating 25(OH)D (central, 77.0 ± 20.9 nmol/L vs 85.0 ± 22.1 nmol/L, <it>p </it>< 0.001; north 79.3 ± 22.1 nmol/L vs 86.8 ± 21.8 nmol/L, <it>p </it>< 0.001; northeast 84.1 ± 23.3 nmol/L vs 87.3 ± 20.9 nmol/L, <it>p </it>= 0.001; south, 76.6 ± 20.5 nmol/L vs 85.2 ± 24.7 nmol/L, <it>p </it>< 0.001). Overall, the prevalence of vitamin D insufficiency was 64.6%, 46.7%, and 33.5% in Bangkok, municipal areas except Bangkok, and outside municipal area in other parts of the country, respectively. In addition, the prevalence of vitamin D insufficiency according to geographical regions was 43.1%, 39.1%, 34.2% and 43.8% in the central, north, northeast and south, respectively. After controlling for covariates in multiple linear regression analysis, the results showed that low serum 25(OH)D levels were associated with being female, younger age, living in urban and Bangkok.</p> <p>Conclusions</p> <p>Vitamin D insufficiency is common and varies across geographical regions in Thailand.</p

Multifaceted activity of N-acetyl-l-cysteine in chronic obstructive pulmonary disease

Introduction: N-acetyl-l-cysteine (NAC), a derivative of the naturally occurring amino acid l-cysteine, is a mucolytic agent that may also act as an antioxidant by providing cysteine intracellularly for increased production of glutathione. It is also used for the treatment of acetaminophen overdose. Areas covered: The recent international recommendations for the treatment of chronic obstructive pulmonary disease (COPD) report that NAC, because of its mucolytic activity, reduces acute exacerbation of COPD (AECOPD) with a modest improvement in health status. However, NAC is a pleiotropic drug with heterogeneous pharmacologic characteristics that certainly include mucolytic activity, but also has anti-infective properties and specific antioxidant and anti-inflammatory effects in the airways. Thus, the mechanisms leading to the protective role of this agent against AECOPD need to be adequately addressed. Expert commentary: The protective effect of NAC against AECOPD seems to be related not only to its well-documented mucolytic activity but also to activation of antioxidant pathways, inhibition of pro-oxidant and inflammatory pathways, and modulation of human bronchial tone. Thus, the dogma that NAC acts prevalently as a mucolytic agent is outdated, and the hypothesis that its anti-inflammatory effect is secondary to the antioxidant activity has been rejected