Interrelationship of serum lipids with relative weight, blood glucose, and physical activity

Coronary risk factors and physical fitness in healthy middle-aged men

In 1832 healthy men aged 40-59 years subjected to a near maximal bicycle exercise test, physical fitness decline with age. Higher levels of physical fitness were in all age groups associated with lower cigarette consumption, blood pressure, serum triglycerides, hemoglobin and with better pulmonary function. Serum cholesterol, however, was independent of changes in physical fitness. In view of the beneficial effect of high physical activity on the well-known coronary risk factors, it is surprising that it has proved so difficult to show a protective effect of increased physical fitness and activity in coronary heart disease and its manifestations.

Comparison of Different Regression Analyses for Identifying Risk Factors in Obese and Nonobese Patients With Coronary Artery Disease

This study was designed to assess conventional and novel risk factors in obese and nonobese patients with coronary artery disease (CAD) by using multivariate forward and univariate logistic regression analysis and to find the best model of analysis for identifying these risk factors. The study group consisted of 398 patients who consecutively underwent coronary angiography for the investigation of chest pain, except overweight patients. In univariate logistic regression analysis, high C-reactive protein and cigarette smoking were found to be the strongest variables in obese and nonobese patients with CAD, respectively. In multivariate forward logistic regression analysis, some risk factors were not found as predictors of CAD. Multivariate forward logistic regression analysis with the advantage of a high predictable ratio may be more useful for the analysis of risk factors in patients with CAD.

Identifying risk factors in a mostly overweight patient population with coronary artery disease

Overweight/obesity is a complex multifactorial chronic disorder, and the American Heart Association (AHA) has recently classified as a modifiable risk factor for coronary heart disease (CAD). This study (1) evaluates the association between CAD in a patient population mostly overweight (MOP) and conventional and novel coronary risk factors by using univariate and multivariate logistic regression analysis and (2) seeks to find the best model by comparing univariate and multivariate logistic regression analysis algorithms, which were systematically applied to risk factors by using Hosmer-Lemeshow statistic test. In univariate analysis, there were significant associations between CAD in MOP and conventional and novel risk factors. However, the model's sensitivity, specificity, and accuracy levels were weak. In multivariate analysis, although some risk factors were not found as predictors of coronary artery disease, the model showed good fit to data and had high sensitivity, specificity, and accuracy levels. This was also confirmed by using the Hosmer-Lemeshow goodness of fit test, more specifically.

Obesity is associated with premature occurrence of acute myocardial infarction

BACKGROUND

The American Heart Association has classified obesity as a major modifiable risk factor for coronary artery disease, but its relationship with age at presentation with acute myocardial infarction (AMI) is poorly documented.

HYPOTHESIS

The study was undertaken to evaluate the impact of obesity on age at presentation, and on in-hospital morbidity and mortality in patients with AMI.

METHODS

Our analysis includes a consecutive series of 906 Olmsted County patients (mean age 67.7 years, 51% male) admitted with AMI to the Mayo Clinic Coronary Care Unit (CCU). The patients were entered into the Mayo CCU Database, a prospective registry of data pertaining to patients admitted to the Mayo Clinic CCU with AMI. Age at AMI occurrence and in-hospital morbidity and mortality were noted.

RESULTS

Obese patients (body mass index [BMI] >30) with AMI were significantly younger than patients with AMI in the overweight (BMI 25-30) and normal-weight (BMI < 30) groups (62.3+/-13.1 vs. 66.9+/-13.2 and 72.9+/-13.4, respectively. p < 0.001). Obesity and overweight status were associated with male gender, diabetes mellitus, hypercholesterolemia, and smoking history; however, after multivariate adjustment for these risk factors, excess weight and premature AMI remained significantly associated. Compared with normal-weight patients, overweight patients presenting with AMI were 3.6 years younger (p < 0.001, confidence interval [CI] 1.9-5.4) and obese patients 8.2 years younger (p < 0.001, Cl 6.2-10.1). No significant increase in in-hospital morbidity and mortality was seen.

CONCLUSION

In this population-based study, overweight and obese status are independently associated with the premature occurrence of AMI, but not with an increased incidence of in-hospital complications.

Obesity is independently associated with coronary endothelial dysfunction in patients with normal or mildly diseased coronary arteries

OBJECTIVES

This study evaluates the impact of obesity on coronary endothelial function in patients with normal or mild coronary artery disease.

BACKGROUND

The American Heart Association (AHA) has recently classified obesity as a modifiable risk factor for coronary heart disease.

METHODS

A total of 397 consecutive patients with normal or mildly diseased coronary arteries at angiography underwent coronary vascular reactivity evaluation using intracoronary adenosine, acetylcholine and nitroglycerin. Patients were divided into three groups based on the body mass index (BMI): Group 1, patients with a BMI <25 (n = 117, normal weight); Group 2, patients with a BMI 25-30 (n = 149, overweight) and Group 3, patients with a BMI >30 (n = 131, obese).

RESULTS

There were no significant differences among the groups in regard to other cardiovascular risk factors, except that overweight but not obese patients were significantly older than normal-weight patients (47 +/- 1 years in Group 1, 53 +/- 1 years in Group 2 and 50 +/- 1 years in Group 3, p < 0.001). The percent change of coronary blood flow to acetylcholine (%delta CBF Ach) was significantly lower in the obese patients than in the normal-weight group (85.2 +/- 12.0% in Group 1, 63.7 +/- 10.0% in Group 2 and 38.1 +/- 9.6% in Group 3, p = 0.009). By multivariate analysis, overweight (odds ratio, 1.55; 95% confidence interval, 1.2-2.0) and obesity (odds ratio, 2.41; 95% confidence interval, 1.5-4.0) status were independently associated with impaired coronary endothelial function.

CONCLUSIONS

The study demonstrates that obesity is independently associated with coronary endothelial dysfunction in patients with normal or mildly diseased coronary arteries.

Prevalence of obesity in Korean non-insulin-dependent diabetic patients

A total of 15,665 Korean non-insulin-dependent diabetic (NIDDM) patients, aged over 30 years, was studied. The percent ideal body weight (%IBW) and body mass index (BMI) at the time of the study were obtained. Also, the percent maximal ideal body weight (%IBWM) and maximal body mass index (BMIM) were derived from the past maximal body weight by taking down the subject's weight histories. Other clinical characteristics such as age and sex distributions were analyzed. Laboratory findings including serum lipids and HgbA1c were determined. The results were as follows: the levels of serum total-cholesterol, LDL-cholesterol and triglyceride rose significantly as obesity increased. Also, the levels of serum total-cholesterol and LDL-cholesterol were significantly higher in the female subjects than those in the male subjects. Prevalence of obesity was 32.3% (5058 cases) at the time of study (%IBW over 120%), while 57.9% (9041 cases) were over 120% of maximal ideal body weight (%IBWM). When considering the BMI, prevalence of obesity was 32.4% (5078 cases) at the time of study (BMI over 25 kg/m2), while 60.5% (9437 cases) was over 25 kg/m2 of maximal body mass index (BMIM). The value of the BMI equivalent to the percent ideal body weight of 120% was 25.8 kg/m2 in male and 24.5 kg/m2 in female NIDDM patients in this study.

Dietary predictors of serum cholesterol in men: the Framingham cohort population

This study examines the cross-sectional relationships between diet and serum cholesterol in a sample of 413 Framingham cohort males, ages 37-70. Regression analyses controlling for age, calories, and coronary heart disease risk factors showed that the direct predictors of serum cholesterol included: fat (g) (p less than 0.05), cholesterol (mg/1000 calories) (p less than 0.05), protein (g and calorie density) (p less than 0.05 and p less than 0.001, respectively), Metropolitan relative weight (p less than 0.05), and systolic blood pressure (p less than 0.001). Fat (calorie density) and cholesterol (mg) were marginally significant direct positive predictors (0.05 less than or equal to p less than or equal to 0.10). Inverse correlates of serum cholesterol were total carbohydrate (g and calorie density) and simple carbohydrate (calorie density) (p less than 0.001). A marginally inverse correlate of serum cholesterol was complex carbohydrate (calorie density) (0.05 less than or equal to p less than or equal to 0.10). These cross-sectional results show that dietary variables predict serum cholesterol levels in men independent of other coronary heart disease risk factors.

Parent--child obesity and cardiovascular risk factors

Blood pressure, cholesterol, high density lipoprotein cholesterol, and triglycerides were studied in obese children and obese parents selected to participate in a weight treatment program. The relationships between parent and child risk levels, as well as the relationship between child and parent weight and risk factors, were established. Results showed that children's cholesterol and triglycerides were related to parental lipid levels, independent of weight. Children's blood pressure readings were strongly related to their weight, but not to parental blood pressure. High density lipoprotein cholesterol levels were negatively related to weight in both child and parent female populations, and weakly positively related to weight for male children. Implications of these risk factor patterns for intervention are discussed.

Relation of diet to LDL cholesterol, VLDL cholesterol, and plasma total cholesterol and triglycerides in white adults. The Lipid Research Clinics Prevalence Study

The association of diet with low density lipoprotein cholesterol (LDL-C) and total triglycerides, as well as with total and very low density lipoprotein cholesterol (VLDL-C), was investigated in a random sample of 4374 white participants aged 20 to 59 years seen by the Lipid Research Clinic Prevalence Study. Carbohydrate and total calories were negatively associated with LDL-C. There was also a statistically significant positive association of LDL-C with the percentage of total calories from fat. These three findings are generally consistent with what other cross-sectional studies have reported for the relation of diet with total cholesterol levels. The only diet variables significantly related to triglyceride levels in both men and women were the percentage of calories from fats, particularly polyunsaturated fatty acids (PFA), the P/S ratio, and the number of grams of PFA per day, all of which were inversely associated with the level of this lipid.

The synergistic effect of weight loss and changes in dietary lipids on the serum cholesterol of obese men with hypercholesterolaemia: implications for prevention of coronary heart disease

The hypolipidaemic effect of a low-fat, low-cholesterol diet, alone and in combination with weight reduction, has been evaluated in two groups of obese men with hypercholesterolaemia. In 41 men who lost 10.3 kg over 11 months and maintained their lower weight for 23.5 months serum cholesterol fell by 1.68 mmol/l and remained steady at lower weight. In 20 similar men, the controls, whose weight fell by 0.8 kg over 39.5 months, serum cholesterol fell by 0.80 mmol/l. There was a significant linear correlation between change in weight and change in serum cholesterol. The change in serum cholesterol in the weight losers was greater than could be accounted for by change in dietary lipids. Weight reduction and low-fat, low-cholesterol diets appear to have a synergistic effect in reducing serum cholesterol.

Relation of lipids, weight and physical activity to incidence of coronary heart disease: the Puerto Rico heart study

The 2 1/2 year incidence of coronary heart disease was examined in relation to antecedent serum cholesterol and fasting triglyceride levels, physical activity status and relative weight in a cohort of 8,171 urban and rural men 45 to 64 years old participating in the Puerto Rico Heart Program. In this population with a low incidence rate of coronary heart disease, risk of coronary disease was related to serum cholesterol in both urban and rural groups, but this trend was statistically significant only in the urban population. Neither the urban nor the rural population showed a substantial or statistically significant association of serum triglyceride levels with incidence of coronary heart disease. Correlations among relative weight and serum triglyceride and serum cholesterol levels were noted. Despite small differences in incidence of coronary heart disease between urban and rural groups, values for serum cholesterol, triglycerides and relative weight were all significantly higher in the urban men. Only physical activity levels were higher in the rural men. Multivariate analysis, performed to sort out the net effects of these interrelated variables, revealed that serum cholesterol is related to the risk of coronary heart disease even when all variables are taken into account. Low levels of physical activity were significantly associated with a greater incidence of coronary heart disease only in urban men (P less than 0.05). Overweight, which was associated with higher lipid values and less physical activity, was not related to the development of coronary heart disease in either the urban or the rural cohort.

Relation of body weight to development of ischemic heart disease in a cohort of young North American men after a 26 year observation period: the Manitoba Study

The role of overweight as a risk factor for ischemic heart disease remains controversial. Therefore, in the Manitoba Study of a cohort of 3,983 men with a mean age at entry of 30.8 years, initial measurements of body weight, represented by body mass index (weight/height2), were compared with the 26 year incidence of ischemic heart disease. After adjustment for the effects of age and blood pressure in univariate and multivariate analysis, body mass index was a significant predictor of the 390 cases of ischemic heart disease. To elucidate this relation further, the cohort was further analyzed after categorization by age at entry, time of occurrence of disease after entry and manifestation of ischemic heart disease. The association with weight was most apparent in men less than 40 years of age and was not evident until 16 years of follow-up. A high body mass index was significantly associated with development of myocardial infarction, sudden death and coronary insufficiency or suspected myocardial infarction; the relation was strongest with sudden death. Among men who had a myocardial infarction, body mass index was more strongly associated with sudden death and was the best predictor of myocardial infarction occurring after 20 years of observation. Thus, after adjustment for the effect of age and blood pressure, overweight is a definite risk factor but primarily in younger men, after long periods of observation and for certain manifestations of ischemic heart disease.