Vegetarianism, coronary disease risk factors and coronary heart disease

Recent studies of vegetarians confirm a lower risk of fatal heart disease amongst such subjects. Lipid levels are lower in vegetarians, even when the diet of comparable meat-eaters is low in fat. This may partly explain the lower mortality, but it is not clear whether the absence of meat or some other aspect of the vegetarian diet is causal in this relationship.     

Diabetes and other coronary heart disease risk equivalents

The close association between diabetes and cardiovascular disease suggests that current predictions of a massive increase in the prevalence of type 2 diabetes foreshadow an equally daunting rise in the incidence of vascular disease. The limited cardiovascular benefits obtained by glucose-lowering treatments, although perhaps not surprising, indicate that other cardiovascular risk factors must be given serious consideration as therapeutic targets. The impressive reductions in the number of vascular events observed in diabetic patients, albeit in small patient populations, participating in various drug trials amply justify such an approach. A necessary prerequisite, however, is a clear understanding of the clinical importance of individual risk factors to the occurrence of vascular disease in type 2 diabetic patients. This would appear essential for defining treatment strategies in the face of a bewildering array of potential therapeutic targets. The present review considers recent studies that have assessed the predictive value of risk factors against a diabetic background.     

Dental disease and risk of coronary heart disease and mortality.

OBJECTIVE--To investigate a reported association between dental disease and risk of coronary heart disease. SETTING--National sample of American adults who participated in a health examination survey in the early 1970s. DESIGN--Prospective cohort study in which participants underwent a standard dental examination at baseline and were followed up to 1987. Proportional hazards analysis was used to estimate relative risks adjusted for several covariates. MAIN OUTCOME MEASURES--Incidence of mortality or admission to hospital because of coronary heart disease; total mortality. RESULTS--Among all 9760 subjects included in the analysis those with periodontitis had a 25% increased risk of coronary heart disease relative to those with minimal periodontal disease. Poor oral hygiene, determined by the extent of dental debris and calculus, was also associated with an increased incidence of coronary heart disease. In men younger than 50 years at baseline periodontal disease was a stronger risk factor for coronary heart disease; men with periodontitis had a relative risk of 1.72. Both periodontal disease and poor oral hygiene showed stronger associations with total mortality than with coronary heart disease. CONCLUSION--Dental disease is associated with an increased risk of coronary heart disease, particularly in young men. Whether this is a causal association is unclear. Dental health may be a more general indicator of personal hygiene and possibly health care practices.     

Dietary factors in the fall in coronary heart disease mortality.

The role of dietary change in the fall in heart disease mortality has been hotly debated. Three countries, Australia, USA and UK with equal 'care' and sophistication of surgical techniques have shown different timing in the beginning of the decline of this 'epidemic'; around the mid 1960s in the first two countries, but not until the late 1970s for the UK. The cause of this difference may be the changing food habits of their populations. Using food disappearance data, apparent consumption of butter and margarine show opposite trends (butter down and margarine up) predating the decline in mortality in both the USA and Australia by at least 7 years and also in the UK, but at a later time, (about 1970). Changes in adipose tissue linoleate, a marker for polyunsaturated fat intake, support this indirect evidence, with depot levels rising in the USA from the 1960s and 10 years later in the UK. Other evidence support the view of decreasing saturated fat intake and increasing polyunsaturated intake prior to 1960 in the USA. Although many factors must contribute to the decline in mortality from CHD, change in dietary P/S ratio would seem to be the major dietary contributor.     

Cytomegalovirus infection and coronary heart disease risk: a meta-analysis

The chronic inflammatory process including cytomegalovirus (CMV) infection has been hypothesized to induce the progression of atherosclerosis in coronary heart disease (CHD). Numbers studies were conducted to analyze the association between CMV infection and risk of CHD, but no clear consensus had been reached. To assess this relationship more precisely, a meta-analysis was performed. The electronic databases PubMed, Embase, and CNKI were searched; data were extracted and analyzed independently by two investigators. Ultimately, 55 studies, involving 9,000 cases and 8,608 controls from six prospective studies (all with a nested case–control design) and 49 retrospective case–control studies were included. Overall, people exposed to CMV infection had an odds ratio (OR) of 1.67 (95% CI, 1.56–1.79) for CHD risk, relative to those not exposed. CMV infection was clearly identified as a risk factor for CHD in both prospective studies (OR, 1.31; 95% CI, 1.132–1.517) and retrospective studies (OR, 1.79; 95% CI, 1.659–1.939), and in both Asian group (OR, 2.69; 95% CI, 2.304–3.144) and non-Asian group (OR, 1.48; 95% CI, 1.371–1.600). Interestingly, in the subgroup analyses by detection methods of CMV, the increased risk (OR, 8.121) was greater among studies using polymerase chain reaction than the risk (OR, 1.561) among studies using enzyme-linked immunosorbent assay. In conclusion, this meta-analysis suggested that CMV infection is associated with an increased risk for CHD, especially among Asian populations.     

Dietary fat and risk of coronary heart disease in men: cohort follow up study in the United States.

OBJECTIVE--To examine the association between fat intake and the incidence of coronary heart disease in men of middle age and older. DESIGN--Cohort questionnaire study of men followed up for six years from 1986. SETTING--The health professionals follow up study in the United States. SUBJECTS--43 757 health professionals aged 40 to 75 years free of diagnosed cardiovascular disease or diabetes in 1986. MAIN OUTCOME MEASURE--Incidence of acute myocardial infarction or coronary death. RESULTS--During follow up 734 coronary events were documented, including 505 non-fatal myocardial infarctions and 229 deaths. After age and several coronary risk factors were controlled for significant positive associations were observed between intake of saturated fat and risk of coronary disease. For men in the top versus the lowest fifth of saturated fat intake (median = 14.8% v 5.7% of energy) the multivariate relative risk for myocardial infarction was 1.22 (95% confidence interval 0.96 to 1.56) and for fatal coronary heart disease was 2.21 (1.38 to 3.54). After adjustment for intake of fibre the risks were 0.96 (0.73 to 1.27) and 1.72 (1.01 to 2.90), respectively. Positive associations between intake of cholesterol and risk of coronary heart disease were similarly attenuated after adjustment for fibre intake. Intake of linolenic acid was inversely associated with risk of myocardial infarction; this association became significant only after adjustment for non-dietary risk factors and was strengthened after adjustment for total fat intake (relative risk 0.41 for a 1% increase in energy, P for trend < 0.01). CONCLUSIONS--These data do not support the strong association between intake of saturated fat and risk of coronary heart disease suggested by international comparisons. They are compatible, however, with the hypotheses that saturated fat and cholesterol intakes affect the risk of coronary heart disease as predicted by their effects on blood cholesterol concentration. They also support a specific preventive effect of linolenic acid intake.     

Dietary recommendations for the community towards the postponement of coronary heart disease.

The public has recently been confronted with many, often conflicting, recommendations about diet and reducing the risk of coronary heart disease (CHD). Dietary recommendations to the community designed to lower the risk of CHD should be specific, clear, and brief. People should be advised to reduce their intake of foods that are high in saturated fats and replace these partially with foods that are relatively high in polyunsaturated fats. This will lower both total fat and dietary cholesterol intakes and will also change the ratio of polyunsaturated to saturated fats.     

Abdominal fat and risk of coronary heart disease in patients with peripheral arterial disease

Objective: We investigated whether the presence of concomitant coronary heart disease (CHD) in patients with peripheral arterial disease (PAD) can be explained by intra‐abdominal fat accumulation and compared different measures of adiposity as predictors of CHD in patients with PAD. Research Methods and Procedures: Data were collected from patients enrolled in the Second Manifestations of ARTerial disease (SMART) study, an ongoing prospective cohort study of patients with manifest vascular disease or vascular risk factors at the University Medical Centre Utrecht. The current analysis includes 315 patients, mean age 59 ± 10 years, who had PAD with (n = 79) or without (n = 236) CHD. Parameters of adiposity were measured, and intra‐abdominal fat and subcutaneous fat were measured ultrasonographically. Metabolic syndrome was defined according to Adult Treatment Panel III. Results: The prevalence of metabolic syndrome was higher among patients with CHD (63%) than among patients without CHD (48%). All parameters of adiposity indicated more fat in patients with CHD, except for subcutaneous fat. Waist circumference was associated with 64% higher prevalence of CHD (confidence interval, 20% to 123%) per 1 standard deviation increase in waist circumference after adjustment for age and sex. The odds ratio for waist circumference remained virtually the same after additional adjustment for the components of the metabolic syndrome and smoking. Discussion: An increased waist circumference, a crude measure of intra‐abdominal fat, is associated with an increased risk of concomitant CHD in patients with PAD.     

Dietary glycemic load and glycemic index and risk of coronary heart disease and stroke in Dutch men and women: the EPIC-MORGEN study

Background

The associations of glycemic load (GL) and glycemic index (GI) with the risk of cardiovascular diseases (CVD) are not well-established, particularly in men, and may be modified by gender.

Objective

To assess whether high dietary GL and GI increase the risk of CVD in men and women.

Methods

A large prospective cohort study (EPIC-MORGEN) was conducted within the general Dutch population among 8,855 men and 10,753 women, aged 21–64 years at baseline (1993–1997) and free of diabetes and CVD. Dietary intake was assessed with a validated food-frequency questionnaire and GI and GL were calculated using Foster-Powell''s international table of GI. Information on morbidity and mortality was obtained through linkage with national registries. Cox proportional hazards analysis was performed to estimate hazard ratios (HRs) for incident coronary heart disease (CHD) and stroke, while adjusting for age, CVD risk factors, and dietary factors.

Results

During a mean follow-up of 11.9 years, 581 CHD cases and 120 stroke cases occurred among men, and 300 CHD cases and 109 stroke cases occurred among women. In men, GL was associated with an increased CHD risk (adjusted HR per SD increase, 1.17 [95% CI, 1.02–1.35]), while no significant association was found in women (1.09 [0.89–1.33]). GI was not associated with CHD risk in both genders, while it was associated with increased stroke risk in men (1.27 [1.02–1.58]) but not in women (0.96 [0.75–1.22]). Similarly, total carbohydrate intake and starch intake were associated with a higher CHD risk in men (1.23 [1.04–1.46]; and 1.24 [1.07–1.45]), but not in women.

Conclusion

Among men, high GL and GI, and high carbohydrate and starch intake, were associated with increased risk of CVD.