Tuesday, August 26, 2008

Manfaat pemberian vitamin B pada penyakit jantung koroner

Suatu studi observasi melaporkan hubungan antara kadar homosistein dan risiko penyakit kardiovaskuler. Pemberian asam folat dan vitamin B12 diketahui dapat menurunkan kadar homosistein. Penelitian ini ingin mengetahui pengaruh asam folat dan vitamin B6 dan B12 untuk pencegahan sekunder pada pasien penyakit jantung koroner (PJK) dan stenosis klep aorta.
 
Penelitian dilakukan terhadap >3000 pasien yang menjalani prosedur angiografi dan berlangsung selama 7 tahun.
 
Setelah 1 tahun terjadi penurunan kadar homosistein kelompok yang mendapat asam folat dan vitamin B12. Tapi penurunan kadar homosistein ini tidak berpengaruh terhadap mortalitas dan cardiovascular events.
 
Kesimpulan penelitian ini tidak mendukung penggunaan vitamin B untuk preventif sekunder pasien dengan PJK.
 
Abstract
 
JAMA. Vol. 300 No. 7, August 20, 2008;300(7):795-804. © 2008 American Medical Association.
Mortality and cardiovascular events in patients treated with homocysteine-lowering B vitamins after coronary angiography.
Marta Ebbing, MD; Øyvind Bleie, MD, PhD; Per Magne Ueland, MD, PhD et al.
 
Context  Observational studies have reported associations between circulating total homocysteine concentration and risk of cardiovascular disease. Oral administration of folic acid and vitamin B12 can lower plasma total homocysteine levels.

Objective  To assess the effect of treatment with folic acid and vitamin B12 and the effect of treatment with vitamin B6 as secondary prevention in patients with coronary artery disease or aortic valve stenosis.

Design, Setting, and Participants  Randomized, double-blind controlled trial conducted in the 2 university hospitals in western Norway in 1999-2006. A total of 3096 adult participants undergoing coronary angiography (20.5% female; mean age, 61.7 years) were randomized. At baseline, 59.3% had double- or triple-vessel disease, 83.7% had stable angina pectoris, and 14.9% had acute coronary syndromes.

Interventions  Using a 2 x 2 factorial design, participants were randomly assigned to 1 of 4 groups receiving daily oral treatment with folic acid, 0.8 mg, plus vitamin B12, 0.4 mg, plus vitamin B6, 40 mg (n = 772); folic acid plus vitamin B12 (n = 772); vitamin B6 alone (n = 772); or placebo (n = 780).

Main Outcome Measures  The primary end point was a composite of all-cause death, nonfatal acute myocardial infarction, acute hospitalization for unstable angina pectoris, and nonfatal thromboembolic stroke.

Results  Mean plasma total homocysteine concentration was reduced by 30% after 1 year of treatment in the groups receiving folic acid and vitamin B12. The trial was terminated early because of concern among participants due to preliminary results from a contemporaneous Norwegian trial suggesting adverse effects from the intervention. During a median 38 months of follow-up, the primary end point was experienced by a total of 422 participants (13.7%): 219 participants (14.2%) receiving folic acid/vitamin B12 vs 203 (13.1%) not receiving such treatment (hazard ratio, 1.09; 95% confidence interval, 0.90-1.32; P = .36) and 200 participants (13.0%) receiving vitamin B6 vs 222 (14.3%) not receiving vitamin B6 (hazard ratio, 0.90; 95% confidence interval, 0.74-1.09; P = .28).

Conclusions  This trial did not find an effect of treatment with folic acid/vitamin B12 or vitamin B6 on total mortality or cardiovascular events. Our findings do not support the use of B vitamins as secondary prevention in patients with coronary artery disease.

Thursday, August 14, 2008

Diet untuk menurunkan BB

Penelitian ini membandingkan efektivitas dan keamanan diet untuk menurunkan berat badan (BB).
 
Penelitian dilakukan random random terhadap 322 subyek obese selama 2 tahun. Ada 3 jenis diet yang digunakan yaitu 1) rendah lemak, rendah kalori; 2) Mediterranean, rendah kalori; atau 3) rendah karbohidrat, tanpa pembatasan kalori.
 
Kepatuhan mengikuti diet >95% tahun pertama dan >84% tahun kedua.
 
Penurunan BB terbesar dicapai dengan diet rendah lemak. Penurunan terkecil oleh diet rendah lemak rendah kalori. Penurunan rasio kolesterol total terhadap HDL terbaik dicapai dengan diet rendah karbohidrat. Sedangkan untuk penderita diabetes yang terbaik adalah diet Mediterranean.

Abstract
 
N Engl J Med 359(3):229-241, 17 July 2008 © 2008
Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet
Iris Shai, R.D., Ph.D., Dan Schwarzfuchs, M.D., Yaakov Henkin, M.D., Danit R. Shahar, R.D., Ph.D., Shula Witkow, R.D., M.P.H., Ilana Greenberg, R.D., M.P.H., Rachel Golan, R.D., M.P.H., Drora Fraser, Ph.D., Arkady Bolotin, Ph.D., Hilel Vardi, M.Sc., Osnat Tangi-Rozental, B.A., Rachel Zuk-Ramot, R.N., Benjamin Sarusi, M.Sc., Dov Brickner, M.D., Ziva Schwartz, M.D., Einat Sheiner, M.D., Rachel Marko, M.Sc., Esther Katorza, M.Sc., Joachim Thiery, M.D., Georg Martin Fiedler, M.D., Matthias Blüher, M.D., Michael Stumvoll, M.D., Meir J. Stampfer, M.D., Dr.P.H., for the Dietary Intervention Randomized Controlled Trial (DIRECT) Group
 
Background Trials comparing the effectiveness and safety of weight-loss diets are frequently limited by short follow-up times and high dropout rates.
Methods In this 2-year trial, we randomly assigned 322 moderately obese subjects (mean age, 52 years; mean body-mass index [the weight in kilograms divided by the square of the height in meters], 31; male sex, 86%) to one of three diets: low-fat, restricted-calorie; Mediterranean, restricted-calorie; or low-carbohydrate, non–restricted-calorie.
Results The rate of adherence to a study diet was 95.4% at 1 year and 84.6% at 2 years. The Mediterranean-diet group consumed the largest amounts of dietary fiber and had the highest ratio of monounsaturated to saturated fat (P<0.05 for all comparisons among treatment groups). The low-carbohydrate group consumed the smallest amount of carbohydrates and the largest amounts of fat, protein, and cholesterol and had the highest percentage of participants with detectable urinary ketones (P<0.05 for all comparisons among treatment groups). The mean weight loss was 2.9 kg for the low-fat group, 4.4 kg for the Mediterranean-diet group, and 4.7 kg for the low-carbohydrate group (P<0.001 for the interaction between diet group and time); among the 272 participants who completed the intervention, the mean weight losses were 3.3 kg, 4.6 kg, and 5.5 kg, respectively. The relative reduction in the ratio of total cholesterol to high-density lipoprotein cholesterol was 20% in the low-carbohydrate group and 12% in the low-fat group (P=0.01). Among the 36 subjects with diabetes, changes in fasting plasma glucose and insulin levels were more favorable among those assigned to the Mediterranean diet than among those assigned to the low-fat diet (P<0.001 for the interaction among diabetes and Mediterranean diet and time with respect to fasting glucose levels).
Conclusions Mediterranean and low-carbohydrate diets may be effective alternatives to low-fat diets. The more favorable effects on lipids (with the low-carbohydrate diet) and on glycemic control (with the Mediterranean diet) suggest that personal preferences and metabolic considerations might inform individualized tailoring of dietary interventions.

Friday, August 08, 2008

Pengaruh sarapan pada murid sekolah

Apakah sarapan mempengaruhi fungsi kognitif dan emosi murid di sekolah?
 
Penelitian dilakukan secara random pada 104 murid berusia 13-20 tahun.
 
Hasil penelitian menunjukkan peningkatan memori visuospatial pada murid laki2, peningkatan kewaspadaan (alertness) pada semua murid. Murid laki2 merasa emosi lebih positif. Namun tidak ada perubahan pada daya perhatian (sustained attention).
 
Kesimpulan sarapan memberikan efek positif pada murid sekolah.
 
 
PEDIATRICS Vol. 122 No. 2 August 2008, pp. 279-284

ARTICLE

Influence of Having Breakfast on Cognitive Performance and Mood in 13- to 20-Year-Old High School Students: Results of a Crossover Trial

Katharina Widenhorn-Müller, PhDa, Katrin Hille, PhDa, Jochen Klenk, MPHb and Ulrike Weiland, MDa

a Centre for Neuroscience and Learning
b Institute of Epidemiology, Ulm University, Ulm, Germany

OBJECTIVE. The goal was to determine whether breakfast had effects on the cognitive performance and mood of high school students.

METHODS. A crossover trial was performed in boarding schools, involving 104 students between 13 and 20 years of age. The participants were randomly assigned to 2 equal-size groups on the morning of the first testing day. One half of the total sample received a standardized breakfast, whereas the other half received no breakfast. Seven days later, the treatment order was reversed. Measurements of cognitive function included standardized tests of attention and concentration, as well as tests of verbal and spatial memory. In addition, mood was rated with a self-administered questionnaire covering the dimensions of positive and negative affect, information uptake, arousal, and alertness. Statistical analysis consisted of repeated-measures analysis of variance.

RESULTS. Breakfast had no effect on sustained attention among high school students. Visuospatial memory was improved in male students. Self-reported alertness improved significantly in the entire study population. Male students reported feeling more positive after consuming breakfast, compared with the fasting condition.

CONCLUSIONS. This crossover trial demonstrated positive short-term effects of breakfast on cognitive functioning and self-reported alertness in high school students.