BMI and IHD

[Guest guest]

Hi folks:

From Al's post, one of the studies examines the relationship between

BMI and ischemic heart disease among a chinese population. It found

a BMI of 20 was associated with the lowest rates of IHD, with

increasing rates both below and above these levels. It should be

noted that only 6.5% of all deaths in this group were from IHD - much

lower than in North America - so these results may, or may not, apply

to people in economically more advanced countries.

October 2005. PMID: 16258057.

Here is the abstract:

" Body mass index and mortality from ischaemic heart disease in a lean

population: 10 year prospective study of 220 000 adult men.

Zhengming Chen1,*, Gonghuan Yang2,3, Maigeng Zhou2, Margaret 1,

Alison Offer1, Jieming Ma2,3, Lijun Wang2,3, Hongchao Pan1,

Whitlock1, Rory 1, Shiru Niu2 and Peto1

1 Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU),

Radcliffe Infirmary, University of Oxford, UK

2 Disease Surveillance Points, Chinese Center for Disease Control,

Beijing, PRC

3 Centre for Chronic Disease and Behaviour Risk Factors Surveillance,

Institute of Basic Medical Sciences, Chinese Academy of Medical

Sciences, Beijing, PRC

* Corresponding author. Clinical Trial Service Unit & Epidemiological

Studies Unit, Doll Building, Old Road Campus, Roosevelt

Drive, Oxford OX3 7LF, UK. E-mail: zhengming.chen@...

Background: Increased body mass index (BMI) is known to be related

to ischaemic heart disease (IHD) in populations where many are

overweight (BMI 25 kg/m2) or obese (BMI 30). Substantial

uncertainty remains, however, about the relationship between BMI and

IHD in populations with lower BMI levels.

Methods: We examined the data from a population-based, prospective

cohort study of 222 000 Chinese men aged 40–79. Relative and absolute

risks of death from IHD by baseline BMI were calculated, standardized

for age, smoking, and other potential confounding factors.

Results: The mean baseline BMI was 21.7 kg/m2, and 1942 IHD deaths

were recorded during 10 years of follow-up (6.5% of all such deaths).

Among men without prior vascular diseases at baseline, there was a J-

shaped association between BMI and IHD mortality. Above 20 kg/m2

there was a positive association of BMI with risk, with each 2 kg/m2

higher in usual BMI associated with 12% (95% CI 6–19%, 2P = 0.0001)

higher IHD mortality. Below this BMI range, however, the association

appeared to be reversed, with risk ratios of 1.00, 1.09, and 1.15,

respectively, for men with BMI 20–21.9, 18–19.9, and <18 kg/m2. The

excess IHD risk observed at low BMI levels persisted after

restricting analysis to never smokers or excluding the first 3 years

of follow-up, and became about twice as great after allowing for

blood pressure.

Conclusions: Lower BMI is associated with lower IHD risk among

people in the so-called normal range of BMI values (20–25 kg/m2), but

below that range the association may well be reversed. "