American Journal of Clinical Nutrition, Vol. 70, No. 6, 1112-1113,
December 1999
© 1999 American Society for Clinical Nutrition
Coronary artery disease risk factors in south Asian and American premenopausal women
Ram B Singh
Heart Research Laboratory, Medical Hospital and Research Centre, Civil Lines, Moradabad 10 (UP) 244001, India, E-mail: rbsingh{at}nde.vsnl.net.inoricn{at}nde.vsnl.net.in
Dear Sir:
We enjoyed very much the most interesting work of Kamath et al (1) on the cardiovascular disease risk factors of south Asian and American premenopausal women. Their study raises several important questions. It is not clear how many subjects were consuming trans fatty acids and Indian ghee nor how much of these substances were being consumed. These substances are known to have adverse effects on coronary artery disease (2). trans Fatty acids also cause increases in lipoprotein(a) [Lp(a)] (3) and n-3 fatty acids from fish oil can decrease Lp(a) concentrations. It would be interesting to know the intake of n-3 fatty acids in the 3 groups. It is not clear why Indians and Pakistanis had lower plasma insulin concentrations than the Americans, despite having greater abdominal fat and lower physical activity levels than the Americans, factors which are known to predispose hyperinsulinemia (4).
People of south Asian origin are accustomed to consuming low-fat diets (<20% of energy/d) and having physically demanding occupations (5). In one population survey (6, 7), of 3257 Indian women aged 25–64 y we found that coronary artery disease risk factors, including dietary fat intake, were significantly greater in the higher social classes 1 and 2 than in the lower social classes 3–5. There were no significant differences in fruit and vegetable intakes between social classes, indicating that dietary fat intake and physical inactivity may be important determinants of coronary artery disease risk in people of south Asian origin. One cross-sectional survey of 515 rural and 595 urban subjects showed that plasma concentrations of HDL were comparable in both men (1.18 ± 0.13 and 1.21 ± 0.22 mmol/L, respectively) and women (1.21 ± 0.16 and 1.28 ± 0.24 mmol/L, respectively) (8). However, 2-h plasma insulin was significantly higher in urban men and women than in rural subjects, indicating that it may be influenced by environmental factors (Table 1
). Plasma concentrations of total cholesterol and triacylglycerols were significantly greater in urban than in rural subjects (Table 1). In a more recent study, plasma zinc concentrations and zinc intakes were inversely associated with high Lp(a) concentrations, indicating that poor zinc intake may cause increased Lp(a) concentrations more in urban than in rural subjects (9). In a randomized, single-blind controlled trial in 463 patients, we showed that a fat-reduced diet plus moderate physical activity decreased plasma insulin and associated disturbances, resulting in significant reductions in cardiac events (10).
REFERENCES
-
Kamath SK, Hussain EA, Amin D, et al. Cardiovascular disease risk factors in 2 distinct ethnic groups: Indian and Pakistani compared with American premenopausal women. Am J Clin Nutr 1999;69:621–31.[Abstract/Free Full Text]
-
Singh RB, Niaz MA, Ghosh S, et al. Association of trans fatty acids (vegetable ghee) and clarified butter (Indian ghee) intake with higher risk of coronary artery disease in rural and urban populations with low fat consumption. Int J Cardiol 1996;56:289–98.[Medline]
-
Mensink R, Zock PL, Katan MB, Hornstra G. Effect of dietary cis and trans fatty acids on serum lipoprotein(a) levels in humans. J Lipid Res 1992;33:1493–501.[Abstract]
-
Singh RB, Rastogi SS, Niaz MA, Postiglione A. Association of central obesity and insulin resistance with high prevalence of diabetes and cardiovascular disease in an elderly population with low fat intake and lower than normal prevalence of obesity: the Indian paradox. Coron Artery Dis 1998;9:559–64.[Medline]
-
Singh RB, Niaz MA, Ghosh S, et al. Low fat intake and coronary artery disease in a population with higher prevalence of coronary artery disease: the Indian paradox. J Am Coll Nutr 1998;17:342–50.[Abstract/Free Full Text]
-
Singh RB, Beegom R, Mehta AS, et al. Social class, coronary risk factors and undernutrition, a double burden of diseases in women during transtition in five Indian cities. Int J Cardiol 1999;69:139–47.[Medline]
-
Singh RB, Verma SP, Niaz MA. Social class and coronary artery disease in India. Lancet 1999;353:154–5.
-
Singh RB, Niaz MA, Rastogi V, et al. Prevalence of coronary artery disease and coronary risk factors in the elderly rural and urban populations of north India. Cardiol Elderly 1996;4:111–7.
-
Singh RB, Niaz MA, Rastogi SS, et al. Current zinc intake and risk of diabetes and coronary artery disease and factors associated with insulin resistance in rural and urban populations of north India. J Am Coll Nutr 1998;17:561–70.
-
Singh RB, Rastogi V, Rastogi SS, et al. Effect of diet and moderate exercise on central obesity and associated disturbances, myocardial infarction and mortality in patients with and without coronary artery disease. J Am Coll Nutr 1996;15:592–601.[Abstract]
