Hyperinsulinaemia is not a major coronary risk factor in elderly men

Summary Insulin and insulin resistance have attracted considerable interest as possible risk factors for coronary heart disease during the last decade. We therefore examined the 8 year incidence of coronary heart disease in 595 67-year-old men in relation to baseline insulin and other risk factors. The incidence of coronary heart disease increased from 9% among non-diabetic men to 13.5% among those with impaired glucose tolerance, 12.9% among newly-detected diabetic men and up to 31.3% among men with known diabetes. The incidence of coronary heart disease was related to fasting blood glucose and 1 h and 2 h blood glucose during the oral glucose tolerance test and to serum cholesterol and serum triglycerides. Fasting serum insulin was of borderline significance for the risk of coronary heart disease. When known diabetic subjects were excluded only serum cholesterol and serum triglycerides remained as statistically significant risk factors. Among diabetic subjects (known and newly-detected) only blood glucose was related to the risk of coronary heart disease. In multivariate analyses the different degrees of glucose intolerance or fasting blood glucose were independently related to the risk of coronary heart disease (p=0.008–0.010). Serum triglycerides were also an independent risk factor in three out of four multivariate models (p=0.02–0.09). Fasting serum insulin was not an independent risk factor. These findings do not support the hypothesis that hyperinsulinaemia is a major risk factor for coronary heart disease in elderly men. Hyperglycaemia (or diabetes mellitus) seems to be the most important risk factor.     

The Framingham Offspring Study: a commentary. 1980

Forty-three of 1,312 men aged 35 to 54 years in the Framingham Offspring Study had clinically recognized coronary heart disease at the initial examination. Twenty-six men in this group had previously had a myocardial infarction. Of 1,296 women in the same age range, only 11 had coronary disease and 3 a prior myocardial infarction. The prevalence of coronary heart disease in men was strongly associated with age, smoking, high density lipoprotein (HDL), low density lipoprotein (LDL) and total cholesterol using univariate analyses. When multivariate logistic regression analysis was used, age, smoking and HDL and LDL cholesterol retained their significant association with coronary heart disease. The total cholesterol/HDL cholesterol ratio was also strongly associated with coronary heart disease in the multivariate analysis. It is concluded that both HDL and LDL cholesterol are strongly and independently associated with the prevalence of coronary heart disease, whereas the level of very low density lipoprotein cholesterol makes no statistically significant independent contribution.     

41-month follow-up of risk factors correlated with new coronary events in 708 elderly patients

A prospective study correlated coronary risk factors with new coronary events in 192 elderly men and 516 elderly women, mean age 82 +/- 8 years. Follow-up was 41 +/- 6 months (range 24-44). Coronary events (myocardial infarction, primary ventricular fibrillation, and sudden cardiac death) occurred in 64 of 192 men (33%) and in 149 of 516 women (29%), P not significant. Using univariate analysis, significant risk factors for coronary events were antecedent coronary artery disease, cigarette smoking, hypertension, diabetes mellitus, serum total cholesterol (TC) greater than or equal to 200 mg/dL and greater than or equal to 250 mg/dL, serum high-density lipoprotein cholesterol (HDL-C) less than 35 mg/dL, and serum TC/HDL-C greater than or equal to 6.5 in men and women, and obesity in women. Using multivariate analysis, significant risk factors for coronary events were age, antecedent coronary artery disease, cigarette smoking, hypertension, diabetes mellitus, and serum TC in men and women and serum HDL-C and serum triglycerides in women. Using univariate analysis, significant risk factors for coronary events in men and women with antecedent coronary artery disease were cigarette smoking, diabetes mellitus, serum TC greater than or equal to 250 mg/dL, and serum TC/HDL-C greater than or equal to 6.5. Using multivariate analysis, significant risk factors for coronary events in men and women with antecedent coronary artery disease were age, cigarette smoking, diabetes mellitus, serum TC, serum HDL-C, and serum triglycerides.(ABSTRACT TRUNCATED AT 250 WORDS)     

5-year incidence of atherosclerotic vascular disease in relation to general risk factors, insulin level, and abnormalities in lipoprotein composition in non-insulin-dependent diabetic and nondiabetic subjects

The 5-year incidence of myocardial infarction and claudication was examined in a group of middle-aged patients (n = 133, 70 men and 63 women) with newly diagnosed non-insulin-dependent diabetes and nondiabetic control subjects (n = 144, 62 men and 82 women). The effects of general risk factors, plasma insulin level, and lipoprotein abnormalities on the incidence of myocardial infarction and claudication were also evaluated by univariate analyses in both diabetic patients and nondiabetic subjects and by multivariate analyses combining both groups. The age-adjusted incidence of myocardial infarction was higher both in diabetic men (19.4%) and diabetic women (11.0%) than in nondiabetic men (3.2%, p = 0.009) and nondiabetic women (3.0%, p = 0.047). Similarly, the age-adjusted incidence of claudication was higher among the diabetic patients (20.3% vs. 8.0% for men, p = 0.06; 21.8% vs. 4.2% for women, p = 0.003). None of the general risk factors (i.e., low density lipoprotein [LDL] cholesterol, blood pressure, smoking, and high density lipoprotein [HDL] cholesterol) showed an association with the risk of myocardial infarction either in the diabetic or nondiabetic groups of subjects, but an ischemic electrocardiographic abnormality at the baseline examination predicted myocardial infarction in diabetic men. In univariate analyses in diabetic subjects, high serum total cholesterol, low HDL cholesterol, high very low density lipoprotein (VLDL) cholesterol, and high total, LDL and VLDL triglycerides, and in nondiabetic subjects, high VLDL cholesterol and LDL triglycerides were associated with the appearance of claudication. In multivariate analyses including both diabetic and control subjects, only diabetes had an independent association with myocardial infarction, whereas smoking, high LDL triglycerides or VLDL cholesterol, and high fasting plasma insulin showed independent relations to claudication. The present results indicate that changes in lipoprotein composition characteristic of non-insulin-dependent diabetes are atherogenic and increase the risk of atherosclerotic vascular disease. Furthermore, high plasma insulin might also be involved in atherogenesis, independent of lipoprotein abnormalities.     

Natural history of myocardial infarction in the coronary drug project: Long-term prognostic importance of serum lipid levels

The relation between baseline fasting serum lipid levels (serum cholesterol and triglycerides) and 5 year rates for four end points—mortality from all causes, mortality from coronary heart disease, sudden death due to coronary heart disease and incidence of nonfatal myocardlal infarction plus coronary death—was studied in 2,789 men. These were patients in the Coronary Drug Project placebo group who were 30 to 64 years old on entry and had recovered from one or more previous documented myocardial infarctions. Serum cholesterol was significantly related to all four end points, in both univarlate and multivariate regression analyses (with control of 38 or 39 other factors in the latter). This significant relation of cholesterol to these end points was shown at low, medium and high levels of serum triglycerides. In contrast, baseline fasting serum triglyceride levels were not positively related to any of these end points. In these postmyocardial infarction patients, findings indicative of cardiovascular status at baseline evaluation, particularly the state of the myocardium, were more powerful prognosticators than serum cholesterol. These findings underscore the importance of efforts to prevent the first coronary episode. They also indicate the possibility after recovery from acute myocardial infarction of improving long-term prognosis through reduction of serum cholesterol.     

Prevalence of coronary heart disease in the framingham offspring study: Role of lipoprotein cholesterols

Forty-three of 1,312 men aged 35 to 54 years in the Framingham Offspring Study had clinically recognized coronary heart disease at the initial examination. Twenty-six men in this group had previously had a myocardial infarction. Of 1,296 women in the same age range, only 11 had coronary disease and 3 a prior myocardial infarction. The prevalence of coronary heart disease in men was strongly associated with age, smoking, high density lipoprotein (HDL), low density lipoproteln (LDL) and total cholesterol using univariate analyses. When multivariate logistic regression analysis was used, age, smoking and HDL and LDL cholesterol retained their significant association with coronary heart disease. The total cholesterol/HDL cholesterol ratio was also strongly associated with coronary heart disease in the multivariate analysis. It is concluded that both HDL and LDL cholesterol are strongly and independently associated with the prevalence of coronary heart disease, whereas the level of very low density lipoprotein cholesterol makes no statistically significant independent contribution.     

Lipids and lipoproteins as predictors of coronary heart disease, stroke, and cancer in the Honolulu Heart Program

A group of 2,122 healthy men in the Honolulu Heart Program who participated in the Cooperative Lipoprotein Phenotyping Study, 1970 to 1972, were followed for 10 years by repeated examinations and surveillance of hospital discharge and mortality records in order to diagnose new cases of coronary heart disease, stroke, cancer, and other deaths. Total cholesterol and low-density lipoprotein cholesterol were significantly associated with all clinical types of coronary heart disease in multivariate analyses, whereas high-density lipoprotein cholesterol was inversely associated with nonfatal myocardial infarction and total coronary heart disease, but not with fatal coronary heart disease nor angina. Triglyceride and very-low-density lipoprotein cholesterol were associated with total coronary heart disease by univariate but not multivariate analysis. None of the other specific chronic diseases were significantly associated with any lipid or lipoprotein, although there were trends of inverse associations of all noncardiovascular disease with total cholesterol and low-density lipoprotein cholesterol. Thus, for total disease (coronary heart disease, stroke, cancer, and other deaths), the optimal range for lowest disease incidence was about 200 to 220 mg/dl for total cholesterol and 120 to 140 mg/dl for low-density lipoprotein cholesterol. A strong inverse pattern of total disease with high-density lipoprotein cholesterol indicated that the highest levels were the optimal levels.     

Predictive value of apolipoproteins in a prospective survey of coronary artery disease in men.

Some studies have suggested that measurements of apolipoproteins may be valuable in the clinical assessment of susceptibility to coronary artery disease, over and above the lipoprotein lipids. Only a few of these studies have been prospective in nature and further knowledge is therefore needed to clarify the issue. The independent prognostic value of apolipoproteins (apo-B, apo-AI and apo[a]) with regard to coronary artery disease was estimated from a prospective survey among 1,332 randomly selected Icelandic men, aged 45 to 72 years, participating in a health survey from 1979 to 1981. The group was followed for 8.6 years, and during that period 104 men had fatal or nonfatal myocardial infarction. The Cox's proportional hazards model was used to estimate the significance of independent variables. The results of multivariate analysis showed that apo(a) was a significant independent risk factor (odds ratio 1.22 for 1 SD), but apo-AI was a stronger negative risk factor (odds ratio 0.70 for 1 SD). Apo-B was a highly significant risk factor in a univariate analysis, but not in a multivariate analysis when serum cholesterol was included. Previous population surveys in Iceland have confirmed the importance of cigarette smoking, cholesterol, triglycerides and blood pressure as risk factors for coronary artery disease. The present results illustrate additional importance of apo-AI and apo(a) concentrations in predicting coronary artery disease among Icelandic men, whereas apo-B did not contribute anything further to the prediction than serum total cholesterol.     

Predictors of coronary bypass grafting in a population of middle-aged men.

BACKGROUND: Coronary bypass grafting is a procedure which is usually undertaken because of extensive coronary heart disease, whereas acute myocardial infarction may occur with patients with moderate or even minimal disease. Having undergone coronary bypass grafting may thus serve as a marker for extensive coronary atherosclerosis. The aim of this study was to assess risk factors for future coronary bypass grafting as a first coronary event, and to compare them with risk factors for a first acute myocardial infarction. DESIGN: This was a prospective cohort study. METHOD: In the Multifactor Primary Prevention Study, 7388 men aged 47-55 years and free of previous acute myocardial infarction or stroke were investigated between 1970 and 1973. During 28 years of follow-up 1664 men (22%) had an acute myocardial infarction or died from coronary disease. One hundred and forty six men (2%) underwent coronary bypass grafting with no prior acute infarction. RESULTS: Serum cholesterol was a stronger predictor of coronary bypass grafting than of acute myocardial infarction. Compared to men with serum cholesterol of 5.0 or lower, men with serum cholesterol 5.1-6.4, 6.5-7.4 and over 7.4 mmol/l had age-adjusted hazard ratios for acute myocardial infarction of 1.22 (1.00-1.49), 1.66 (1.35-2.03) and 2.04 (1.65-2.51). Corresponding hazard ratios for coronary bypass grafting were 1.57 (0.66-3.70), 3.44 (1.47-8.03) and 5.21 (2.20-12.31) (95% confidence interval). In contrast, smoking was a weaker risk factor for coronary bypass grafting than for acute myocardial infarction with no discernible increase in risk except in very heavy smokers (25 g/day or more; n=193); hazard ratio 2.19 (1.02-4.66). Elevated blood pressure predicted coronary bypass grafting and acute myocardial infarction equally well. In multivariate analysis an increase in serum cholesterol of 1 mmol/l was associated with an odds ratio of 1.56 (1.38-1.76) for coronary bypass grafting but only 1.30 (1.24-1.36) for AMI (P for difference in odds ratio 0.004). CONCLUSION: Elevated serum cholesterol is a stronger predictor for future coronary bypass grafting than for acute myocardial infarction. Moderate smoking was not associated with coronary bypass grafting. Different manifestations of coronary disease have different risk factor patterns, suggesting that secular changes in risk factor pattern could potentially influence the clinical expression of the disease.     

Serum cholesterol and acute myocardial infarction: a case-control study from the GISSI-2 trial. Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto-Epidemiologia dei Fattori di Rischio dell'Infarto Miocardico Investigators.

OBJECTIVE--To examine the role of serum cholesterol in acute myocardial infarction in a population of patients with no history of coronary heart disease and to establish the nature of this association, the degree of risk, and the possible interaction between serum cholesterol and other major risk factors for acute myocardial infarction. DESIGN--Case-control study. SETTING--90 hospitals in northern, central, and southern Italy. PATIENTS--916 consecutive cases of newly diagnosed acute myocardial infarction and 1106 hospital controls admitted to hospital with acute conditions not related to known or suspected risk factors for coronary heart disease. DATA COLLECTION--Data were collected with a structured questionnaire and blood samples were taken by venepuncture as soon as possible after admission to hospital from cases and controls. Blood cholesterol concentrations were available for 614 cases and 792 controls. RESULTS--After adjustment by logistic regression for sex, age, education, geographical area, smoking status, body mass index, history of diabetes and hypertension, and family history of coronary heart disease the estimated relative risks of acute myocardial infarction for quintiles of serum cholesterol (from lowest to highest) were 2.3 (95% confidence interval (CI) 1.6 to 3.4), 3.1 (95% CI 2.1 to 4.6), 4.1 (95% CI 2.8 to 6.0), and 5.2 (95% CI 3.5 to 7.7). The estimated relative risk across selected covariates increased from the lowest to the highest quintile of serum cholesterol particularly for men, patients under 55 years of age, and smokers. When the possible interaction of known risk factors with serum cholesterol was examined, smoking habits, diabetes, and hypertension had approximately multiplicative effects on relative risk. CONCLUSIONS--This study indicates that serum cholesterol was an independent risk factor for acute myocardial infarction. This association was linear, with no threshold level. Moreover, there was a multiplicative effect between cholesterol and other major risk factors on the relative risk of acute myocardial infarction.     

Relation of serum total cholesterol and other risk factors to risk of coronary events in middle-aged and elderly Japanese men with hypercholesterolemia: the Kyushu Lipid Intervention Study.

BACKGROUND: The role of serum total cholesterol (TC) in the development of coronary heart disease (CHD) may differ in different age groups. METHODS AND RESULTS: The relation of serum TC and other risk factors to CHD events was examined in middle-aged (<65 years) and elderly (> or =65 years) men separately in the Kyushu Lipid Intervention Study (KLIS). Subjects were 4,349 men aged 45-74 years with serum TC of 220 mg/dl or greater who had no history of myocardial infarction, coronary angioplasty, or stroke. There were 123 CHD events (ie, myocardial infarction, coronary bypass surgery, coronary angioplasty, cardiac death, and sudden death) in a 5-year follow-up period. The Cox proportional hazards model was used with baseline and follow-up serum TC, baseline high-density lipoprotein (HDL) cholesterol, hypertension, diabetes mellitus, and other factors as covariates. Serum TC concentration during the follow-up, not at baseline, was associated with an increased risk of CHD events, especially in elderly men. High concentrations of serum HDL cholesterol were associated with a modest, statistically nonsignificant decrease in the risk among middle-aged men. An increased risk of CHD events associated with diabetes mellitus was greater in middle-aged men. Hypertension and smoking were not measurably related to the risk in either middle-aged or elderly men. CONCLUSIONS: Both the serum TC concentration during follow-up and diabetes mellitus are important predictors of CHD events in Japanese men with moderately elevated serum TC.     

Risk of new myocardial infarction in middle-aged men with manifest coronary heart disease.

Men incuring coronary heart disease (CHD) during surveillance of an employed population were studied for risk factors associated with additional myocardial infarctions. The coronary-prone Type A behavior pattern measured by a test score, number of cigarettes smoked daily, and serum cholesterol were significantdiscriminators between the 67 men with recurrent CHD and the 220 with but a single clinical CHD event. Diastolic blood pressure and fasting serum triglycerides were not significant discriminators. Statistical analyses directed to possible sources of bias occasioned by the combined retrospective-prospective study design revealed that these problems are negligible and do not alter the findings observed. Type A score appears relatively unaffected by whether the measure was made before or after the initial CHD event. Multivariable discriminant function equations showed Type A score to be the strongest single predictor of recurrent CHD among the variables available. Number of cigarettes smoked and serum cholesterol accounted for additional variance. Future field trials for the secondary prevention of myocardial infarction would be strengthened by consideration of the possible role of Type A behavior.     

Homocysteine and major coronary events: a prospective population study amongst women

OBJECTIVES: To study serum homocysteine concentration for its prediction of major coronary heart disease events amongst women. DESIGN: A case-control study nested within a follow-up study. Subjects. A total of 74 and 75 major coronary events (coronary deaths or nonfatal myocardial infarction) which occurred in women with and without known heart disease, respectively, during a 13-year follow-up and two individually matched controls per case. Main outcome measure. Major coronary event. RESULTS: Amongst women with baseline heart disease, the relative risk (95% CI) of such events, adjusted for age, smoking, hypertension, diabetes, serum cholesterol and body mass index, was 3.32 (1.05-10.5) in the highest homocysteine quintile compared with the lowest quintile. Amongst women free of heart disease at baseline, the corresponding relative risk value was 0.77 (0.24-2.45). CONCLUSIONS: This prospective study support the hypothesis that homocysteine is a risk factor for coronary events in women with heart disease.     

Blood Glucose,Glucose Tolerance and Manifest Diabetes in Relation to Cardiovascular Disease and Death in Women: A 12-Year Follow-up of Participants in the Population Study of Women in Gothenburg,Sweden

ABSTRACT. A longitudinal population study of 1462 women, aged 38–60, was carried out in Gothenburg, Sweden in 1968–69. Women with initially manifest diabetes mellitus had significantly increased 12-year incidence of myocardial infarction and increased mortality while no increased incidence of angina pectoris, ECG changes indicating ischaemic heart disease or stroke was observed. The association to myocardial infarction remained in multivariate analyses and was independent of age, body fat distribution, smoking, serum cholesterol and systolic blood pressure. The association to mortality was independent of these factors and also of serum triglycerides. Women who were diagnosed as “new diabetics” during the 12-year follow-up had a significantly increased 12-year incidence of myocardial infarction but no significant increase was observed for any of the other end-points studied. When women with initially manifest diabetes mellitus were excluded, no association was found between initial fasting blood glucose concentration and the end-points studied. A negative significant association was found between initial fasting blood glucose concentration and smoking.     

C-reactive protein, cardiovascular risk factors and the association with myocardial infarction in men

OBJECTIVES: This study had three objectives: first, to investigate the association of C-reactive protein levels and myocardial infarction amongst men; secondly, to study the associations of C-reactive protein levels with cardiovascular risk factors; and thirdly, to adjust the risk of myocardial infarction for such factors. DESIGN AND SUBJECTS: A case-control study including 560 patients with a first myocardial infarction who had survived at least 6 months, plus 646 control subjects. RESULTS: Patients had significantly higher levels of C-reactive protein (mean 2.2 mg L-1) than control subjects (mean 1.7 mg L-1; P < 0.001). Persons in the highest quintile of C-reactive protein had an unadjusted 1.9-fold increased risk of myocardial infarction compared with persons in the lowest quintile (odds ratio 1.9, 95% CI: 1.3-2.7). C-reactive protein was, in addition to smoking, associated with several cardiovascular risk factors: age, obesity, diabetes, blood pressure, triglycerides and inversely associated to HDL cholesterol. Adjustment for these variables, especially for total cholesterol, HDL cholesterol and triglycerides, substantially decreased the risk of myocardial infarction for persons in the highest quintile of C-reactive protein, compared to those in the lowest quintile, to 1.3 (95% CI: 0.9-1.9). CONCLUSIONS: Our findings confirm previous reports that C-reactive protein predicts the risk of myocardial infarction. However, this association does not appear to be causal, since the increase in risk can to a large extent be explained by the presence of other cardiovascular risk factors.     

LDL size and risk of coronary heart disease in elderly men and women

A predominance of small, dense, low density lipoprotein (LDL) particles has consistently been associated with coronary heart disease (CHD) in young and middle-aged subjects in cross-sectional studies. Recently, 3 prospective, case-control studies showed that decreased LDL size is a predictor of CHD in middle-aged subjects. However, it is not known whether decreased LDL size is mainly associated with premature CHD or whether it continues to play a role in CHD risk at older ages also. We performed a prospective, nested case-control study in 86 subjects (58 nondiabetic and 28 type 2 diabetic) aged 65 to 74 years who were free of myocardial infarction at baseline and who then had a myocardial infarction or CHD death during a 3.5-year follow-up (cases) and in 172 controls matched for sex and diabetes status but who remained free of CHD during follow-up. LDL particle size determined by gradient gel electrophoresis (268.2+/-0.9 versus 268.5+/-0.7 A, P=0.782) and the proportion of subjects with LDL subclass phenotype B (20.9 versus 21. 5, P=0.914) were similar among cases and controls. Furthermore, diastolic blood pressure, total cholesterol, high density lipoprotein cholesterol, triglycerides, apolipoprotein A(1), fasting glucose, fasting insulin, waist-to-hip ratio, and body mass index were not associated with CHD risk. However, smoking and increased systolic blood pressure, apolipoprotein B levels, and the total cholesterol-high density lipoprotein cholesterol ratio were significant predictors of CHD events both in univariate and multivariate analyses. Our findings indicate that LDL size is not a predictor of CHD events in elderly white subjects after controlling for diabetes status.     

High density lipoprotein cholesterol and myocardial infarction or sudden coronary death: a prospective case-control study in middle-aged men of the Oslo study.

The high density lipoprotein (HDL) cholesterol concentrations of frozen specimen obtained in 1972-73 are reported from 93 men aged 40-49 years who later developed coronary heart disease (CHD), and for 186 controls. Mean HDL cholesterol of CHD-patients was 7.9% lower than that of controls matched for smoking habits and serum concentrations of triglycerides and total cholesterol (p 0.05 for 82 men who had myocardial infarction, n.s. difference for 11 with sudden coronary death), and 10.2% lower (p 0.05) than that of controls who were not matched for the parameters mentioned. The present prospective study confirms that HDL cholesterol is inversely associated with the risk of developing CHD in middle-aged men.     

High stored iron levels are associated with excess risk of myocardial infarction in eastern Finnish men.

BACKGROUND. Iron can induce lipid peroxidation in vitro and in vivo in humans and has promoted ischemic myocardial injury in experimental animals. We tested the hypothesis that high serum ferritin concentration and high dietary iron intake are associated with an excess risk of acute myocardial infarction. METHODS AND RESULTS. Randomly selected men (n = 1,931), aged 42, 48, 54, or 60 years, who had no symptomatic coronary heart disease at entry, were examined in the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) in Eastern Finland between 1984 and 1989. Fifty-one of these men experienced an acute myocardial infarction during an average follow-up of 3 years. On the basis of a Cox proportional hazards model adjusting for age, examination year, cigarette pack-years, ischemic ECG in exercise test, maximal oxygen uptake, systolic blood pressure, blood glucose, serum copper, blood leukocyte count, and serum high density lipoprotein cholesterol, apolipoprotein B, and triglyceride concentrations, men with serum ferritin greater than or equal to 200 micrograms/l had a 2.2-fold (95% CI, 1.2-4.0; p less than 0.01) risk factor-adjusted risk of acute myocardial infarction compared with men with a lower serum ferritin. An elevated serum ferritin was a strong risk factor for acute myocardial infarction in all multivariate models. This association was stronger in men with serum low density lipoprotein cholesterol concentration of 5.0 mmol/l (193 mg/dl) or more than in others. Also, dietary iron intake had a significant association with the disease risk in a Cox model with the same covariates. CONCLUSIONS. Our data suggest that a high stored iron level, as assessed by elevated serum ferritin concentration, is a risk factor for coronary heart disease.     

Hyperhomocystinemia: a risk factor or a consequence of coronary heart disease?

BACKGROUND: Mild hyperhomocystinemia has been suggested as an indicator of an increased risk of cardiovascular disease. OBJECTIVE: To examine whether serum homocysteine concentration is a predictor of coronary heart disease (CHD) events. METHODS: A case-control study, nested in a population-based cohort study was used. During a follow-up of 13 years, 166 major coronary events (death from CHD or nonfatal myocardial infarction) occurred in men with evidence of heart disease at baseline and 272 events in men without a history of heart disease. Two controls per case were selected by individual matching. RESULTS: Among men with known heart disease at baseline, the relative risk (95% confidence interval) of CHD events adjusted for age, smoking, hypertension, diabetes mellitus, serum cholesterol level, body mass index, and alcohol consumption was 2.23 (95% confidence interval, 1.03-4.85) in the highest serum homocysteine quintile compared with the lowest quintile. Among the men free of heart disease at baseline, the corresponding relative risk was 0.90 (95% confidence interval, 0.51-1.60). CONCLUSIONS: This prospective study does not support the hypothesis that a high concentration of serum homocysteine is a risk factor for coronary events in a population free of heart disease. However, it does suggest that mild hyperhomocystinemia predicts secondary coronary events in men with heart disease, possibly as a consequence of atherosclerotic changes.     

Smoking, blood pressure and serum cholesterol as risk factors of acute myocardial infaction and death among men in Eastern Finland

The impact of smoking, serum cholesterol and blood pressureon the risk of acute myocardial infarction and death due toall causes and cardiovascular diseases was studied in a randomsample of men aged 35 to 59 years from the North Karelia andKuopio counties of Eastern Finland. This is an area with anexceptionally high incidence of coronary heart disease. Altogether,4034 men were studied with a participation rate of 92%. Thesemen were followed-up with a myocardial infarction register anddeath certificate data. During the first five years 256 deathsoccurred among all subjects. There were 66 acute myocardialinfarctions in the North Karelian men reporting no recent coronaryheart disease. Smoking, elevated serum cholesterol and bloodpressure were independently and jointly related to an increasedrisk of acute myocardial infarction and death due to all causesand to cardiovascular disease. Smokers had a 2–3-foldage-adjusted risk of acute myocardial infarction, a 2-2-foldrisk of any death and a 2.1-fold risk of cardiovascular deathcompared with non-smokers. The age-adjusted risk ratios forsystolic blood pressure of 160 mm Hg or more were 1.3, 1.4 and1.9 and those for serum cholesterol at least 8 mmol/l (309 mg/100ml) 2.6, 1.5 and 2.6 concerning myocardial infarction, all deathsand cardiovascular deaths, respectively. All risk ratios exceptthat of systolic blood pressure for acute myocardial infarctionwere significant at levels of at least P < 0.05