We investigated the association between cigarette smoking and the risk of developing rheumatoid arthritis (RA) in the Malaysian population. A total of 1,056 RA patients and 1,416 matched controls aged 18-70 years within a defined area of Peninsular Malaysia were evaluated in a case-control study between August 2005 and December 2009. A case was defined as a person with early diagnosed RA using the 1987 American College of Rheumatology criteria for RA. Controls were randomly selected matched for sex, age, and residential area. Cases and controls answered a questionnaire on a broad range of issues, including lifestyle factors and smoking habits wherein current and former smoking was classified as ever-smoking. The presence of anti-citrullinated peptide antibodies (ACPA) was determined for cases and controls. We found that ever-smokers had an increased risk of developing ACPA-positive RA [odds ratio (OR) = 4.1, 95% confidence interval (CI) 1.9-9.2] but not ACPA-negative RA (OR = 0.7, 95% CI 0.3-2.0), compared with never-smokers. A significant dose-response relationship between cumulative dose of smoking and risk of ACPA-positive RA was observed (<20 pack-years OR = 3.3, 95% CI 1.1-9.8; at least 20 pack-years OR = 5.2, 95% CI 1.6-17.6). Hence, smoking is associated with an increased risk of ACPA-positive RA in the Malaysian population, in which the genetic context is similar to several other Asian countries.
Bats (Order: Chiroptera) is a recognised group of bioindicators due to their sensitivity towards alterations in their immediate surroundings. With the threats of climate change becoming more severe on a daily basis, it is reasonable to collect data on how bat diversity is influenced by elevation. This will be useful to predict and monitor possible upslope shifting of bat species due to increase in surrounding temperature or anthropogenic pressure. Hence, this study aims to uncover the bat diversity trend at different elevations in Crocker Range Park (CRP), Sabah, Malaysia. Bat trappings were conducted in four substations within this park, covering an elevation spectrum from 450 to 1900 m a.s.l. The overall sampling managed to capture 133 individuals of bats, predominantly Pteropodidae, with the addition of two new species locality records for CRP, Murinapeninsularis and Hypsugovondermanni. Simple linear regression analyses revealed that both bat diversity and richness have an inverse linear relationship with elevation. Likewise, the Pearson's correlation value, associating bat diversity with elevation, also shows that they have a negative relationship at r = -0.852. Heterogeneity of habitats explain this trend, as in the lower counterpart of CRP, lowland forests, which are richer in fruit and insect resources persist. Besides, lower land forests have better niche assortment, due to the distinctive layers stratification, allowing bats utilising different guilds to thrive in the same vegetation profile. This study further emphasises the role of CRP to protect most of the bat species found in Borneo, as well as serving as the baseline data for the future studies that look into the impact of temperature increment towards the upslope shifting of the bat population in CRP.