Thursday, October 5, 2006

Multivitamin dan Mineral: Dapatkah Mencegah Kanker dan Penyakit Kronik?

Suplemen multivitamin dan mineral sekarang banyak
dikonsumsi masyarakat. Seberapa efektif untuk mencegah
kanker dan penyakit kronik? Amankah dikonsumsi? Penelitian
di bawah ini membedah 12 artikel studi efikasi dan 8 studi
keamanan.

Hasil penelitian di Cina pada masyarakat dengan status
gizi buruk, suplementasi ß-carotene, tocopherol, dan
selenium, mengurangi angka insiden kanker lambung dan
mortalitas kanker lain2 sebesar 13-21%.
Hasil penelitian di Perancis, suplementasi vitamin C,
vitamin E, ß-carotene, selenium, dan zinc mengurangi
kejadian kanker sebesar 31% untuk laki2, tapi tidak
bermakna untuk wanita.
Suplementasi multivitamin dan mineral tidak bermakna untuk
penyakit kardiovaskuler atau katarak.
Suplementasi ß-carotene, selenium, -tocopherol, retinol,
and zinc mengurangi mortalitas stroke sebesar 29%
(penelitian Linxian).
Suplementasi zinc dan anti-oksidan dapat memperlambat
progresi AMD.

Efek samping pemberian multivitamin dan mineral tidak
terbukti.

Berdasarkan bukti2 tersebut efektivitas suplementasi
kombinasi multivitamin dan mineral untuk mencegah kanker
dan penyakit kronik kurang kuat.

Abstract

The Efficacy and Safety of Multivitamin and Mineral
Supplement Use To Prevent Cancer and Chronic Disease in
Adults: A Systematic Review for a National Institutes of
Health State-of-the-Science Conference

Ann Intern Med 5 September 2006. Volume 145 Issue 5,
372-385. © 2006 American College of Physicians – American
Society of Internal Medicine

Han-Yao Huang, PhD, MPH; Benjamin Caballero, MD, PhD;
Stephanie Chang, MD; Anthony J. Alberg, PhD, MPH; Richard
D. Semba, MD, MPH; Christine R. Schneyer, MD; Renee F.
Wilson, MSc; Ting-Yuan Cheng, MSc; Jason Vassy, MPH;
Gregory Prokopowicz, MD, MPH; George J. Barnes, II, BA;
and Eric B. Bass, MD, MPH.

Background: Multivitamin and mineral supplements are the
most commonly used dietary supplements in the United
States.
Purpose: To synthesize studies on the efficacy and safety
of multivitamin/mineral supplement use in primary
prevention of cancer and chronic disease in the general
population.
Data Sources: English-language literature search of the
MEDLINE, EMBASE, and Cochrane databases through February
2006 and hand-searching of pertinent journals and
articles.
Study Selection: Randomized, controlled trials in adults
were reviewed to assess efficacy, and randomized,
controlled trials and observational studies in adults or
children were reviewed to assess safety.
Data Extraction: Paired reviewers extracted data and
independently assessed study quality.
Data Synthesis: 12 articles from 5 randomized, controlled
trials that assessed efficacy and 8 articles from 4
randomized, controlled trials and 3 case reports on
adverse effects were identified. Study quality was rated
fair for the studies on cancer, cardiovascular disease,
cataracts, or age-related macular degeneration and poor
for the studies on hypertension. In a poorly nourished
Chinese population, combined supplementation with
ß-carotene, -tocopherol, and selenium reduced the
incidence of and mortality rate from gastric cancer and
the overall mortality rate from cancer by 13% to 21%. In a
French trial, combined supplementation with vitamin C,
vitamin E, ß-carotene, selenium, and zinc reduced the rate
of cancer by 31% in men but not in women. Multivitamin and
mineral supplements had no significant effect on
cardiovascular disease or cataracts, except that combined
ß-carotene, selenium, -tocopherol, retinol, and zinc
supplementation reduced the mortality rate from stroke by
29% in the Linxian study and that a combination of 7
vitamins and minerals stabilized visual acuity loss in a
small trial. Combined zinc and antioxidants slowed the
progression of advanced age-related macular degeneration
in high-risk persons. No consistent adverse effects of
multivitamin and mineral supplements were evident.
Limitations: Only randomized, controlled trials were
considered for efficacy assessment. Special nutritional
needs, such as use of folic acid by pregnant women to
prevent birth defects, were not addressed. Findings may
not apply to use of commercial multivitamin supplements by
the general U.S. population.
Conclusions: Evidence is insufficient to prove the
presence or absence of benefits from use of multivitamin
and mineral supplements to prevent cancer and chronic
disease.

Wednesday, October 4, 2006

Distribusi lemak tubuh dan risiko terjadinya diabetes tipe 2

Penelitian ini bertujuan untuk mengetahui indikator apa (indeks massa tubuh,
lingkar pinggang dan rasio lingkar pinggang lingkar panggul) yang paling
relevan sebagai prediktor diabetes tipe 2 untuk pria dan wanita.

Subyek penelitian dari MONICA Augsburg sebanyak 3.055 pria dan 2.957 wanita,
berusia 35-74 tahun, yang tidak menderita diabetes, difollow-up selama lebih
dari 9 tahun.

Ternyata baik lemak tubuh maupun lemak perut berhubungan dengan diabetes
tipe 2. Maka untuk prediksi diabetes tipe 2 baik pada pria maupun wanita
yang terbaik adalah melakukan pengukuran indeks massa tubuh dan lingkar
pinggang.

Abstract

Body fat distribution and risk of type 2 diabetes in the general population:
are there differences between men and women? The MONICA/KORA Augsburg Cohort
Study

Christa Meisinger, Angela Döring, Barbara Thorand, Margit Heier and
Hannelore Löwel
American Journal of Clinical Nutrition, Vol. 84, No. 3, 483-489, September
2006
© 2006

Background: It remains controversial whether body mass index (BMI), waist
circumference (WC), or waist-hip ratio (WHR) is a better risk predictor of
type 2 diabetes.

Objective: The objective was to examine the sex-specific relevance of WC,
WHR, and BMI to the development of type 2 diabetes.

Design: The prospective population-based cohort study was based on 3055 men
and 2957 women aged 35-74 y who participated in the second (1989-1990) or
third (1994-1995) MONICA (Monitoring Trends and Determinants on
Cardiovascular Diseases) Augsburg survey. The subjects were free of diabetes
at baseline. Hazard ratios (HRs) were estimated from Cox proportional
hazards models.

Results: During a mean follow-up of 9.2 y, 243 cases of incident type 2
diabetes occurred in men and 158 occurred in women. Multivariable-adjusted
HRs across quartiles of BMI were 1.0, 1.37, 2.08, and 4.15 in men and 1.0,
3.77, 4.95, and 10.58 in women; those of WC were 1.0, 1.15, 1.57, and 3.40
in men and 1.0, 3.21, 3.98, and 10.70 in women; those of WHR were 1.0, 1.14,
1.80, and 2.84 in men and 1.0, 0.82, 2.06, and 3.51 in women. In joint
analyses, the highest risk was observed in men and women with a high BMI in
combination with a high WC and a high WHR.

Conclusions: Both overall and abdominal adiposity were strongly related to
the development of type 2 diabetes. Because there was an additive effect of
overall and abdominal obesity on risk prediction, WC should be measured in
addition to BMI to assess the risk of type 2 diabetes in both sexes.

Rasio lingkar pinggang-panggul menggambarkan risiko kematian

Penelitian ini bertujuan menilai hubungan antara indeks massa tubuh, lingkar pinggang, dan rasio lingkar pinggang-lingkar panggul terhadap risiko kematian.

Subyek penelitian sebanyak 14.833 orang manula (75 th) dan difollow-up selama hampir 6 tahun.

Kesimpulan penelitian menunjukkan bahwa rasio lingkar pinggang-lingkar panggul berhubungan dengan risiko kematian pada pria dan wanita. Sedangkan indeks massa tubuh dan lingkar pinggang tidak signifikan. Hasil ini mengingatkan pentingnya pengukuran lingkar pinggang dan lingkar panggul.

Abstract

Weight, shape, and mortality risk in older persons: elevated waist-hip ratio, not high body mass index, is associated with a greater risk of death

Gill M Price, Ricardo Uauy, Elizabeth Breeze, Christopher J Bulpitt and Astrid E Fletcher

American Journal of Clinical Nutrition, Vol. 84, No. 2, 449-460, August 2006 © 2006

Background: Guidelines for optimal weight in older persons are limited by uncertainty about the ideal body mass index (BMI) or the usefulness of alternative anthropometric measures.
Objective: We investigated the association of BMI (in kg/m2), waist circumference, and waist-hip ratio (WHR) with mortality and cause-specific mortality.
Design: Subjects aged 75 y (n = 14 833) from 53 family practices in the United Kingdom underwent a health assessment that included measurement of BMI and waist and hip circumferences; they also were followed up for mortality.
Results: During a median follow-up of 5.9 y, 6649 subjects died (46% of circulatory causes). In nonsmoking men and women (90% of the cohort), compared with the lowest quintile of BMI (<23 in men and <22.3 in women), adjusted hazard ratios (HRs) for mortality were <1 for all other quintiles of BMI (P for trend = 0.0003 and 0.0001 in men and women, respectively). Increasing WHR was associated with increasing HRs in men and women (P for trend = 0.008 and 0.0002, respectively). BMI was not associated with circulatory mortality in men (P for trend = 0.667) and was negatively associated in women (P for trend = 0.004). WHR was positively related to circulatory mortality in both men and women (P for trend = 0.001 and 0.005, respectively). Waist circumference was not associated with all-cause or circulatory mortality.

Conclusions: Current guidelines for BMI-based risk categories overestimate risks due to excess weight in persons aged 75 y. Increased mortality risk is more clearly indicated for relative abdominal obesity as measured by high WHR.