Wednesday, January 5, 2011

Body-Mass Index and Mortality among 1.46 Million White Adults

Penelitian ini menegaskan bahwa berat badan lebih (maupun kurang) diukur dari nilai indeks massa tubuh (IMT) meningkatkan mortalitas. Mortalitas terendah adalah IMT 20,0 sampai 24,9.
 
Namun penelitian ini adalah pada subyek Kaukasia. Bagaimana untuk orang Asia ?

ORIGINAL ARTICLE
Body-Mass Index and Mortality among 1.46 Million White Adults
Amy Berrington de Gonzalez, D.Phil., Patricia Hartge, Sc.D., James R. Cerhan, Ph.D., Alan J. Flint, Dr.P.H., Lindsay Hannan, M.S.P.H., Robert J. MacInnis, Ph.D., Steven C. Moore, Ph.D., Geoffrey S. Tobias, B.S., Hoda Anton-Culver, Ph.D., Laura Beane Freeman, Ph.D., W. Lawrence Beeson, Dr.P.H., Sandra L. Clipp, M.P.H., Dallas R. English, Ph.D., Aaron R. Folsom, M.D., D. Michal Freedman, Ph.D., Graham Giles, Ph.D., Niclas Hakansson, Ph.D., Katherine D. Henderson, Ph.D., Judith Hoffman-Bolton, Jane A. Hoppin, Sc.D., Karen L. Koenig, Ph.D., I-Min Lee, Sc.D., Martha S. Linet, M.D., Yikyung Park, Sc.D., Gaia Pocobelli, M.S., Arthur Schatzkin, M.D., Howard D. Sesso, Sc.D., Elisabete Weiderpass, Ph.D., Bradley J. Willcox, M.D., Alicja Wolk, Dr.Med.Sci., Anne Zeleniuch-Jacquotte, M.D., Walter C. Willett, M.D., Dr.P.H., and Michael J. Thun, M.D.
N Engl J Med 2010; 363:2211-2219

BACKGROUND
A high body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) is associated with increased mortality from cardiovascular disease and certain cancers, but the precise relationship between BMI and all-cause mortality remains uncertain.
METHODS
We used Cox regression to estimate hazard ratios and 95% confidence intervals for an association between BMI and all-cause mortality, adjusting for age, study, physical activity, alcohol consumption, education, and marital status in pooled data from 19 prospective studies encompassing 1.46 million white adults, 19 to 84 years of age (median, 58).
RESULTS
The median baseline BMI was 26.2. During a median follow-up period of 10 years (range, 5 to 28), 160,087 deaths were identified. Among healthy participants who never smoked, there was a J-shaped relationship between BMI and all-cause mortality. With a BMI of 22.5 to 24.9 as the reference category, hazard ratios among women were 1.47 (95 percent confidence interval [CI], 1.33 to 1.62) for a BMI of 15.0 to 18.4; 1.14 (95% CI, 1.07 to 1.22) for a BMI of 18.5 to 19.9; 1.00 (95% CI, 0.96 to 1.04) for a BMI of 20.0 to 22.4; 1.13 (95% CI, 1.09 to 1.17) for a BMI of 25.0 to 29.9; 1.44 (95% CI, 1.38 to 1.50) for a BMI of 30.0 to 34.9; 1.88 (95% CI, 1.77 to 2.00) for a BMI of 35.0 to 39.9; and 2.51 (95% CI, 2.30 to 2.73) for a BMI of 40.0 to 49.9. In general, the hazard ratios for the men were similar. Hazard ratios for a BMI below 20.0 were attenuated with longer-term follow-up.
CONCLUSIONS
In white adults, overweight and obesity (and possibly underweight) are associated with increased all-cause mortality. All-cause mortality is generally lowest with a BMI of 20.0 to 24.9.

Tuesday, November 30, 2010

Dietary Intervention in Infancy and Later Signs of Beta-Cell Autoimmunity

Paparan dini terhadap protein tertentu pada bayi dengan genetic susceptibility untuk diabetes tipe 1 akan meningkatkan risiko timbulnya autoimun terhadap sel beta.
Penelitian ini menguji hipotesis bahwa susu formula protein terhidrolisa akan menurunkan insiden timbulnya autoantibodi untuk bayi2 tersebut.
Terbukti intervensi diet pada bayi2 tersebut mempengaruhi marker autoimun terhadap sel beta yang dalam jangka panjang akan menuju pada timbulnya diabetes tipe 1.


N Engl J Med 363:1900-1908, 11 November 2010 © 2010 to the Massachusetts Medical Society
Dietary Intervention in Infancy and Later Signs of Beta-Cell Autoimmunity.
Mikael Knip, Suvi M. Virtanen, Karri Seppa, et al.

BACKGROUND
Early exposure to complex dietary proteins may increase the risk of beta-cell autoimmunity and type 1 diabetes in children with genetic susceptibility. We tested the hypothesis that supplementing breast milk with highly hydrolyzed milk formula would decrease the cumulative incidence of diabetes-associated autoantibodies in such children.
METHODS
In this double-blind, randomized trial, we assigned 230 infants with HLA-conferred susceptibility to type 1 diabetes and at least one family member with type 1 diabetes to receive either a casein hydrolysate formula or a conventional, cow's-milk–based formula (control) whenever breast milk was not available during the first 6 to 8 months of life. Autoantibodies to insulin, glutamic acid decarboxylase (GAD), the insulinoma-associated 2 molecule (IA-2), and zinc transporter 8 were analyzed with the use of radiobinding assays, and islet-cell antibodies were analyzed with the use of immunofluorescence, during a median observation period of 10 years (mean, 7.5). The children were monitored for incident type 1 diabetes until they were 10 years of age.
RESULTS
The unadjusted hazard ratio for positivity for one or more autoantibodies in the casein hydrolysate group, as compared with the control group, was 0.54 (95% confidence interval [CI], 0.29 to 0.95), and the hazard ratio adjusted for an observed difference in the duration of exposure to the study formula was 0.51 (95% CI, 0.28 to 0.91). The unadjusted hazard ratio for positivity for two or more autoantibodies was 0.52 (95% CI, 0.21 to 1.17), and the adjusted hazard ratio was 0.47 (95% CI, 0.19 to 1.07). The rate of reported adverse events was similar in the two groups.
CONCLUSIONS
Dietary intervention during infancy appears to have a long-lasting effect on markers of beta-cell autoimmunity — markers that may reflect an autoimmune process leading to type 1 diabetes.

N-3 Fatty Acids and Cardiovascular Events after Myocardial Infarction

Asam lemak omega3 terbukti mempunyai efek protektif untuk penyakit kardiovaskuler. Penelitian ini ingin melihat efek protektif untuk pasien yang sudah mengalami infark miokard.
Ternyata pemberian omega3 dosis kecil dalam bentuk EPA, DHA maupun ALA tidak menurunkan kejadian kardiovaskuler bagi pasien yang sudah mengalami infark miokard.


N Engl J Med 363:2015-2026, 18 November 2010 © 2010 to the Massachusetts Medical Society
N-3 Fatty Acids and Cardiovascular Events after Myocardial Infarction.
Daan Kromhout, Erik J. Giltay, and Johanna M. Geleijnse, for the Alpha Omega Trial Group.

BACKGROUND
Results from prospective cohort studies and randomized, controlled trials have provided evidence of a protective effect of n−3 fatty acids against cardiovascular diseases. We examined the effect of the marine n−3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and of the plant-derived alpha-linolenic acid (ALA) on the rate of cardiovascular events among patients who have had a myocardial infarction.
METHODS
In a multicenter, double-blind, placebo-controlled trial, we randomly assigned 4837 patients, 60 through 80 years of age (78% men), who had had a myocardial infarction and were receiving state-of-the-art antihypertensive, antithrombotic, and lipid-modifying therapy to receive for 40 months one of four trial margarines: a margarine supplemented with a combination of EPA and DHA (with a targeted additional daily intake of 400 mg of EPA–DHA), a margarine supplemented with ALA (with a targeted additional daily intake of 2 g of ALA), a margarine supplemented with EPA–DHA and ALA, or a placebo margarine. The primary end point was the rate of major cardiovascular events, which comprised fatal and nonfatal cardiovascular events and cardiac interventions. Data were analyzed according to the intention-to-treat principle, with the use of Cox proportional-hazards models.
RESULTS
The patients consumed, on average, 18.8 g of margarine per day, which resulted in additional intakes of 226 mg of EPA combined with 150 mg of DHA, 1.9 g of ALA, or both, in the active-treatment groups. During the follow-up period, a major cardiovascular event occurred in 671 patients (13.9%). Neither EPA–DHA nor ALA reduced this primary end point (hazard ratio with EPA–DHA, 1.01; 95% confidence interval [CI], 0.87 to 1.17; P=0.93; hazard ratio with ALA, 0.91; 95% CI, 0.78 to 1.05; P=0.20). In the prespecified subgroup of women, ALA, as compared with placebo and EPA–DHA alone, was associated with a reduction in the rate of major cardiovascular events that approached significance (hazard ratio, 0.73; 95% CI, 0.51 to 1.03; P=0.07). The rate of adverse events did not differ significantly among the study groups.
CONCLUSIONS
Low-dose supplementation with EPA–DHA or ALA did not significantly reduce the rate of major cardiovascular events among patients who had had a myocardial infarction and who were receiving state-of-the-art antihypertensive, antithrombotic, and lipid-modifying therapy.