Friday, April 17, 2009

Indeks massa tubuh sebagai prediktor mortalitas

Hubungan antara indeks massa tubuh (IMT) dan mortalitas terlihat dalam penelitian prospektif berikut yang melibatkan 900 ribu subyek dewasa.
 
Kematian terendah adalah pada IMT 22,5 - 25 kg/m2.
 
Setiap peningkatan IMT 5 kg/m2 meningkatkan kematian (overall mortality) 30%.
Untuk kematian akibat penyakit vaskuler meningkat 40%.
Untuk kematian akibat diabetik, penyakit ginjal, dan penyakit hati meningkat 60-120%.
Untuk kematian akibat penyakit keganasan meningkat 10%.
Untuk penyakit pernapasan meningkat 20%.
 
IMT <22,5 kg/m2 terjadi peningkatan kematian akibat penyakit pernapasan dan kanker paru, terutama bagi perokok.
 
IMT 30-35 kg/m2 angka survival berkurang 2-4 tahun. IMT 40-45 kg/m2 angka survival berkurang 8-10 tahun (setara efek merokok)
 
 
The Lancet, Volume 373, Issue 9669, Pages 1083 - 1096, 28 March 2009
 
Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies
 

Background

The main associations of body-mass index (BMI) with overall and cause-specific mortality can best be assessed by long-term prospective follow-up of large numbers of people. The Prospective Studies Collaboration aimed to investigate these associations by sharing data from many studies.

Methods

Collaborative analyses were undertaken of baseline BMI versus mortality in 57 prospective studies with 894 576 participants, mostly in western Europe and North America (61% [n=541 452] male, mean recruitment age 46 [SD 11] years, median recruitment year 1979 [IQR 1975—85], mean BMI 25 [SD 4] kg/m2). The analyses were adjusted for age, sex, smoking status, and study. To limit reverse causality, the first 5 years of follow-up were excluded, leaving 66 552 deaths of known cause during a mean of 8 (SD 6) further years of follow-up (mean age at death 67 [SD 10] years): 30 416 vascular; 2070 diabetic, renal or hepatic; 22 592 neoplastic; 3770 respiratory; 7704 other.

Findings

In both sexes, mortality was lowest at about 22·5—25 kg/m2. Above this range, positive associations were recorded for several specific causes and inverse associations for none, the absolute excess risks for higher BMI and smoking were roughly additive, and each 5 kg/m2 higher BMI was on average associated with about 30% higher overall mortality (hazard ratio per 5 kg/m2 [HR] 1·29 [95% CI 1·27—1·32]): 40% for vascular mortality (HR 1·41 [1·37—1·45]); 60—120% for diabetic, renal, and hepatic mortality (HRs 2·16 [1·89—2·46], 1·59 [1·27—1·99], and 1·82 [1·59—2·09], respectively); 10% for neoplastic mortality (HR 1·10 [1·06—1·15]); and 20% for respiratory and for all other mortality (HRs 1·20 [1·07—1·34] and 1·20 [1·16—1·25], respectively). Below the range 22·5—25 kg/m2, BMI was associated inversely with overall mortality, mainly because of strong inverse associations with respiratory disease and lung cancer. These inverse associations were much stronger for smokers than for non-smokers, despite cigarette consumption per smoker varying little with BMI.

Interpretation

Although other anthropometric measures (eg, waist circumference, waist-to-hip ratio) could well add extra information to BMI, and BMI to them, BMI is in itself a strong predictor of overall mortality both above and below the apparent optimum of about 22·5—25 kg/m2. The progressive excess mortality above this range is due mainly to vascular disease and is probably largely causal. At 30—35 kg/m2, median survival is reduced by 2—4 years; at 40—45 kg/m2, it is reduced by 8—10 years (which is comparable with the effects of smoking). The definite excess mortality below 22·5 kg/m2 is due mainly to smoking-related diseases, and is not fully explained.

Thursday, April 16, 2009

Kebiasaan minum teh panas dan kanker esofagus

Bagi penggemar minuman bersuhu tinggi sebaiknya berhati2 karena suhu tinggi berhubungan dengan timbulnya kanker esofagus.

Hal ini dibuktikan dalam penelitian di Iran. Minum teh panas berisiko 2 kali sedangkan minum teh sangat panas berisiko 8 kali terjadinya kanker esofagus. Minum teh lebih 2-3 menit setelah dituang berisiko 2,5 kali. Minum teh kurang 2 menit setelah dituang berisiko 5,5 kali.

 

Tea drinking habits and oesophageal cancer in a high risk area in northern Iran: population based case-control study

Farhad Islami, research fellow1,2,3, Akram Pourshams, associate professor1, Dariush Nasrollahzadeh, PhD student1,4, Farin Kamangar, research fellow5, Saman Fahimi, PhD student1,6, Ramin Shakeri, research fellow1, Behnoush Abedi-Ardekani, pathologist1, Shahin Merat, associate professor1, Homayoon Vahedi, associate professor1, Shahryar Semnani, associate professor and director7, Christian C Abnet, investigator5, Paul Brennan, group head2, Henrik Møller, professor and director3, Farrokh Saidi, professor1, Sanford M Dawsey, senior investigator5, Reza Malekzadeh, professor and director1, Paolo Boffetta, group head and cluster coordinator2

1 Digestive Disease Research Center, Shariati Hospital, Tehran University of Medical Sciences, 14117 Tehran, Iran, 2 International Agency for Research on Cancer, Lyon, France, 3 King's College London, Thames Cancer Registry, London, 4 Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden, 5 Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA, 6 Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge, Cambridge, 7 Golestan Research Center of Gastroenterology and Hepatology, Gorgan University of Medical Sciences, Gorgan, Iran

Objective To investigate the association between tea drinking habits in Golestan province, northern Iran, and risk of oesophageal squamous cell carcinoma.

Design Population based case-control study. In addition, patterns of tea drinking and temperature at which tea was drunk were measured among healthy participants in a cohort study.

Setting Golestan province, northern Iran, an area with a high incidence of oesophageal squamous cell carcinoma.

Participants 300 histologically proved cases of oesophageal squamous cell carcinoma and 571 matched neighbourhood controls in the case-control study and 48 582 participants in the cohort study.

Main outcome measure Odds ratio of oesophageal squamous cell carcinoma associated with drinking hot tea.

Results Nearly all (98%) of the cohort participants drank black tea regularly, with a mean volume consumed of over one litre a day. 39.0% of participants drank their tea at temperatures less than 60°C, 38.9% at 60-64°C, and 22.0% at 65°C or higher. A moderate agreement was found between reported tea drinking temperature and actual temperature measurements (weighted {kappa} 0.49). The results of the case-control study showed that compared with drinking lukewarm or warm tea, drinking hot tea (odds ratio 2.07, 95% confidence interval 1.28 to 3.35) or very hot tea (8.16, 3.93 to 16.9) was associated with an increased risk of oesophageal cancer. Likewise, compared with drinking tea four or more minutes after being poured, drinking tea 2-3 minutes after pouring (2.49, 1.62 to 3.83) or less than two minutes after pouring (5.41, 2.63 to 11.1) was associated with a significantly increased risk. A strong agreement was found between responses to the questions on temperature at which tea was drunk and interval from tea being poured to being drunk (weighted {kappa} 0.68).

Conclusion Drinking hot tea, a habit common in Golestan province, was strongly associated with a higher risk of oesophageal cancer.