Effects of Diet and Lifestyle on the Incidence of Hypertension in Women
Abstract & Commentary
By Harold L. Karpman, MD, FACC, FACP, Clinical Professor of Medicine, UCLA School of Medicine; Dr. Karpman reports no financial relationship to this field of study.
Synopsis: Adherence to appropriate low-risk dietary and other lifestyle factor changes was associated with significant reductions in the incidence of self-reported hypertension and could have the potential to prevent a large proportion of new onset hypertension in women.
Source: Forman JP, et al. Diet and lifestyle risk factors associated with incident hypertension in women. JAMA 2009;302:401-411.
Hypertension is associated with more deaths in women than is any other preventable risk factor.1 Pharmacological treatment of established hypertension has proven benefits, yet blood pressure control is achieved in only 57% of patients with pharmacological intervention,2 and, therefore, primary prevention of hypertension could have major positive public health ramifications by reaching more women and would have the proven benefit of avoiding drug therapy with its potentially adverse effects. Many independent modifiable risk factors for hypertension in women have been identified including being overweight or obese,3 inadequate physical activity,4,5 excess alcohol intake or alcohol abstinence,6 use of non-narcotic analgesics,7 and low folic acid intake.8 Although the effects of intervention to modify one or several of these factors have been documented in the literature,9 the proportion of new onset hypertension cases that could conceivably be prevented by the modification of a combination of lifestyle risk factors has not been clearly evaluated.
Forman and colleagues examined the association between combinations of improved lifestyle factors and the risk of developing hypertension during 14 years of follow-up among women in the second Nurses' Health Study.10 The Nurses' Health Study II is an ongoing prospective cohort study of 116,671 female registered nurses that began in 1989, although 1991 was considered to be its baseline year because dietary effects were first evaluated that year. The participants were followed via biennial questionnaires that gathered information on health-related behaviors (including diet and exercise) and medical events. A remarkable 90% of the 83,882 eligible (i.e., those who returned the 1991 questionnaire and provided dietary information and who did not have hypertension, diabetes mellitus, history of myocardial infarction, elevated cholesterol level, a cancer diagnosis, and were not taking hypertensive drugs) participants aged 27-44 years responded to the follow-up questionnaires from 1991 through 2005. Dietary assessment was made using an extremely thorough questionnaire every 4 years and the intake of supplements was determined by the brand, type, and frequency of reported use. Based on the diet prescribed in the Dietary Approaches to Stop Hypertension (DASH) trial,11 a DASH score was constructed for each participant in 1991 and updated every 4 years. At baseline, the mean age of the population was 36 years and the mean BMI was 23.7 kg/m2. During 14 years of follow-up, 12,319 women (15% of the population) reported a new diagnosis of hypertension. The strongest risk factor was a higher BMI because 40% of new hypertension cases were associated with overweight or obesity, yet only 17% of new hypertension cases noted routine non-narcotic analgesic use, 14% did not follow a DASH-style diet, 10% had no or excessive alcohol consumption, and 4% were noted to have a low supplemental folic acid use.
Commentary
In this large-scale prospective study of women reported by Forman and his colleagues,10 the presence of combinations of modifiable lifestyle factors such as maintenance of a normal BMI; eating a diet high in fruits, vegetables, low-fat dairy products and low in sodium; engaging in vigorous physical exercise on a daily basis; drinking a modest amount of alcohol; avoiding non-narcotic analgesics; and taking supplemental folic acid were associated with dramatic reductions in the incidence of hypertension. Numerous previous studies have also confirmed that these 6 simple lifestyle modifications had the effect of preventing a large proportion of new onset hypertension among young women. It should be recognized that the study had significant limitations such as not evaluating oral contraceptive use or other potentially important modifiable risk factors (e.g., inadequate vitamin D intake, waist circumference, etc.), which also may have made important but unrecognized contributions to the final results. Also, the duration of the study (14 years) may have been too short and, because of measurement error inherent in the questionnaires, some women may have had their BMI, level of physical activity, and non-narcotic analgesic use misclassified. Finally, it must be recognized that the study was conducted only in women and did not include evaluation of lifestyle changes on men; however, it should be noted that a study published in the same issue of the Journal of the American Medical Association (JAMA) revealed that appropriate modification of 6 lifestyles factors (i.e., normal weight, not smoking, regular exercise, moderate alcohol intake, consumption of breakfast cereal, and consumption of fruit and vegetables) in the men in the Physicians' Health Study resulted in a graded inverse relationship with the development of heart failure.12 This relationship was particularly robust and persisted when lifestyle factors were examined over time; when the factors were restricted to adiposity, smoking, and exercise; and when the analyses were restricted to persons with a prior myocardial infarction, type 2 diabetes mellitus, or hypertension. However, both of these purely observational studies pertained solely to healthy and mostly Caucasian men and women; therefore, the results may not be fully applicable to other segments of the U.S. or world population.
In conclusion, adherence to appropriate low-risk dietary and other lifestyle factor changes was associated with significant reductions in the incidence of self-reported hypertension in women and CHF in men, and could have the potential to prevent a large proportion of new onset hypertension and CHF, at least in the populations of women and men included in these two studies. Of course, prevention of hypertension in younger and middle ages would almost certainly have major public health benefits, which have been clearly defined by previously reported studies. If all of the women in the Forman study were in the low-risk category for the 6 lifestyle factors enumerated above, a staggering 78% of new onset hypertension could potentially be prevented or at least delayed. It seems appropriate to at least vigorously recommend adherence to these 6 simple lifestyle changes (and others not included in the Nurses' Study) outlined above both for women and also for men based upon the results of the two studies published in the July22/29, 2009, issue of JAMA.10,12 There is certainly nothing to lose and much to gain.
References
1. Lowe LP, et al. Impact of major cardiovascular disease risk factors, particularly in combination, on 22-year mortality in women and men. Arch Intern Med 1998;158:2007-2014.
2. Ong KL, et al. Prevalence, awareness, treatment, and control of hypertension among United States adults 1994-2004. Hypertension 2007;49:69-75.
3. Gelber RP, et al. A prospective study of body mass index and the risk of developing hypertension in men. Am J Hypertens 2007;20:370-377.
4. Parker ED, et al. Physical activity in young adults and incident hypertension over 15 years of follow-up: The CARDIA study. Am J Public Health 2007;97:703-709.
5. Pereira MA, et al. Physical activity and incident hypertension in black and white adults: The Atherosclerosis Risk in Communities Study. Prev Med 1999;28:304-312.
6. Sesso HD, et al. Alcohol consumption and the risk of hypertension in women and men. Hypertension. 2008; 51:1080-1087.
7. Forman JP, et al. Non-narcotic analgesic dose and risk of incident hypertension in US women. Hypertension 2005;46:500-507.
8. Forman JP, et al. Folate intake and the risk of incident hypertension among US women. JAMA 2005;293:320-329.
9. Elmer PJ, et al. PREMIER Collaborative Research Group. Effects of comprehensive lifestyle modification on diet, weight, physical fitness, and blood pressure control: 18-month results of a randomized trial. Ann Intern Med 2006;144:485-495.
10. Forman JP, et al. Diet and lifestyle risk factors associated with incident hypertension in women. JAMA 2009;302: 401-411.
11. Appel LJ, et al. A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group. N Engl J Med 1997;336:1117-1124.
12. Djousse L, et al. Relation between modifiable lifestyle factors and lifetime risk of heart failure. JAMA 2009;302: 394-400.
Adherence to appropriate low-risk dietary and other lifestyle factor changes was associated with significant reductions in the incidence of self-reported hypertension and could have the potential to prevent a large proportion of new onset hypertension in women.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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