Abdominal Obesity Is the Bane of Latin America

March 05, 2007

March 5, 2007 (Temuco, Chile) – A new analysis of the Latin American countries participating in the INTERHEART study shows that, in contrast to other areas of the world, abdominal obesity was the most important population-attributable risk (PAR) factor for acute MI [1]. Dr Fernando Lanas (Universidad de La Frontera, Temuco, Chile) and colleagues report their findings in the March 7, 2007 issue of Circulation, which has a Latin American theme.

A second paper in the same issue comes to a similar conclusion--abdominal obesity and smoking were the two leading PARs for MI among Hispanic Americans living in Costa Rica with no history of diabetes, hypertension, or medical therapy [2].

"These two articles call attention to the major problems of increased cardiovascular risk in Latin America, which is a cause for concern," accompanying editorialist Dr Sidney C Smith (University of North Carolina School of Medicine, Chapel Hill) told heartwire . The studies provides valuable insight into the risk factors for MI and emphasize "the need for major lifestyle and behavioral modification [there] if the growing toll of coronary heart disease is to be reversed," he comments in his editorial [3].


Six factors more than doubled risk of MI


The analysis by Lanas et al was part of INTERHEART, an international case-control study to assess the impact of well-established and emerging risk factors for MI in various regions of the world.

The researchers evaluated 1237 patients admitted to a medical facility with a first MI in Argentina, Brazil, Colombia, Chile, Guatemala, and Mexico and compared and matched them to 1888 people in a control group, who had no history of coronary disease or angina.

Ten risk factors combined were responsible for 88% of the acute MIs in Latin America.  And six individual factors more than doubled the risk of heart attack.

Comparison of Latin America INTERHEART study risk-factor profiles with the overall INTERHEART study, excluding Latin America  

Risk factor
OR, Latin America
OR, IH-ROW
PAR, Latin America
PAR, IH-ROW
ApoB/apoA-1*
2.31
3.0
40.8
44.2
Smoking†
2.31
2.26
38.4
35.3
Diabetes mellitus
2.59
3.16
12.9
12.2
Hypertension
2.81
2.41
32.9
22.0
WHR*
2.49
2.22
48.5
30.2
Depression
1.17
1.60
4.7
8.4
Permanent stress‡
2.81
2.10
28.1
7.8
Regular exercise
0.67
0.70
28.0
24.8
Alcohol
1.05
0.78
-3.2
16.3
Lack of daily fruit/vegetables
0.63
0.78
6.9
4.1

IH-ROW=INTERHEART rest of world (excluding LA); PAR=population-attributable risk; WHR=waist/hip ratio

*Upper tertile of participants compared with lower tertile

†Never vs current or former

‡Never vs permanent

PARs increasingly important to cardiologists
Smith explained to heartwire that "population-attributable risk is a term introduced by epidemiologists with increasing importance to cardiologists." In contrast to odds ratio--which indicates the risk of given factor causing an event in a given person--PAR details how the prevalence of risk factors in a population might account overall for, in this instance, heart disease.

The three highest PARs in this new analysis--for abdominal obesity, dyslipidemia, and smoking--accounted for 78% of the PARs overall and were deemed to have a large impact. Moderate-impact PARs included history of hypertension (32.9%), stress (28.1%), and lack of exercise (28%).

"Compared with other areas of the world studied in INTERHEART, we were surprised to find how much higher the PAR was for abdominal obesity and stress," Lanas says in an AHA media release. However, he cautions that, following a heart attack, patients may be more likely to report stress, potentially leading to overestimating stress as a risk factor.
PARs provide scientific bases for preventive strategies

Two factors--exercising regularly and eating fruits and vegetables every day--significantly lowered the risk of heart attack. The PAR was reduced 75% in those who did not smoke, exercised regularly, and ate fruits and vegetables every day.

Lanas et al say that their results are generally consistent with the findings of other studies conducted in Latin America and seem to be related to major demographic, epidemiological, and nutritional transitions during the past three decades.

Smith told heartwire : "Now that we have identified these factors, if we were to address the population as a whole, we need to know which are the most prevalent ones.

"Given that all these factors are modifiable, the INTERHEART Latin American study provides a scientific basis to develop preventive strategies that are practical and generally similar in all countries in the entire region," Lanas said.

Cause for optimism too

Smith says the data indicate that a joint message should be used--a call for smoking cessation to be combined with improved dietary intake. But although there is cause for concern, Smith also emphasizes "cause for optimism, with some innovative programs developed in the region."

He discusses a program, established by the government in Brazil in 2000, in which a wide range of activities aimed at behavioral changes was initiated in the hope that they would result in healthier eating and increased physical activity.

Smith told heartwire he was particularly impressed by a scheme in Rio de Janeiro whereby a municipal law was passed that interrupts traffic during certain hours so that people may safely use the streets for exercise, with particular emphasis on economically disadvantaged areas.

"We need to think about how we might intervene, and this means starting with children and nutrition," he says.

  1. Lanas F, Alvezum A, Bautista L, et al. Risk factors for acute myocardial infarction in Latin America. The INTERHEART Latin America Study. Circulation 2007; DOI:10.1161/CIRCULATION AHA.106.633552. Available at: http://circ.ahajournals.org.

  2. Kabagambe EK, Baylin A, Campos H. Nonfatal acute myocardial infarction in Costa Rica: modifiable risk factors, population-attributable risks, and adherence to dietary guidelines. Circulation 2007; DOI: 10.1161/CIRCULATIONAHA.106.643544. Available at: http://circ.ahajournals.org.

  3. Smith SC. Risk factors for myocardial infarction in Latin America. Circulation 2007; DOI:10.1161/CIRCULATION AHA.106.683623. Available at: http://circ.ahajournals.org.



The complete contents of Heartwire , a professional news service of WebMD, can be found at www.theheart.org, a Web site for cardiovascular healthcare professionals.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....