High density lipoprotein cholesterol, insulin and obesity in Samoans

Trends in Body Mass Index in Developing Countries

The purpose of this study was to examine the extent to which adult body mass index (BMI) has changed in developing countries over the past several decades. The analysis is based on a compilation and analysis of mean BMI in 1,432 published samples from developing countries measured between 1957 and 1994. A hierarchical multiple-regression model is applied to these data, controlling for country and study as random covariates and modelling age, sex, socio-economic status, and year as fixed effects. The results reveal a statistically significant increase in mean BMI between 1957 and 1994 in all major regions of the developing world. The size of the increase was 1.4 kg/m2 over the 37-year period, with a 95% confidence interval of 0.4 to 2.4 kg/m2. Mean BMI appears to have increased in all major regions of the developing world, although the size of the increase varies across regions. Using assumptions about the statistical distribution of BMI within populations and cut-off points recommended by the World Health Organization, the analysis suggests that the increase in mean BMI may have resulted in a slight decrease in the prevalence of underweight (BMI<18.5 kg/m2) but is unlikely to have produced an increase in obesity (BMI>30 kg/m2) in most regions. By contrast, the use of lower cut-off points to define obesity, as is done in many individual studies, would suggest that obesity has increased in developing countries. These results highlight the importance of using standardized definitions for underweight and obesity among adults, the need to assess and consider the prevalence of both conditions simultaneously during planning and policy development, and the need to identify policy instruments appropriate to the nutritional profile within a country.

Body fat distribution is a determinant of the high-density lipoprotein response to dietary fat and cholesterol in women

We have conducted a dietary trial that addressed the factors influencing the variability in plasma lipids in response to dietary fat and cholesterol with a focus on the effects of gender and body fat distribution. Sixty-seven women and 53 men were selected so that overall men and women had a similar mean age, LDL cholesterol, and body mass index. After a 2-week low-fat period subjects were given two liquid supplements for 3 weeks each, one that contained 31 to 40 g fat and 650 to 845 mg cholesterol, and one that was fat free. Measurements included plasma lipids and lipoproteins, glucose, insulin, hepatic triglyceride lipase activity, apolipoprotein E polymorphism, and three indexes of body fat (body mass index, waist girth, and waist-hip ratio). In response to dietary fat and cholesterol supplementation only the changes in HDL cholesterol, especially in HDL2, differed between the sexes. Although on univariate analysis lipoprotein changes were predicted by baseline lipoprotein levels, body mass index, waist girth, waist-hip ratio, hepatic triglyceride lipase activity, and insulin, multiple regression showed only waist-hip ratio to predict changes in HDL2 cholesterol in women and body mass index and baseline HDL2 cholesterol in men. Changes in LDL were predicted by baseline LDL cholesterol in women and apolipoprotein E phenotype and age in men. These studies explain much of the variability that individuals show in lipoprotein changes, especially in the more desirable changes in cholesterol transport in HDL2, in response to eating saturated fat and cholesterol.

Insulin resistance, lipoproteins, body fat and hemostasis in nonobese men with angina and a normal or abnormal coronary angiogram

OBJECTIVES

The aim of this study was to compare metabolic risk factors in men with anginal chest pain and a normal or abnormal coronary angiogram with those in healthy men.

BACKGROUND

Risk factors for coronary heart disease, including lipoprotein abnormalities, hypertension and adiposity, may be metabolically interlinked, with insulin resistance and hyperinsulinemia being pivotal to these disturbances.

METHODS

Glucose and insulin metabolism, lipids and lipoproteins, hemostasis, blood pressure and body fat distribution were measured in 77 nonobese middle-aged men who had anginal chest pain (39 with an abnormal coronary angiogram and 38 with no detectable angiographic abnormality) and were compared with those of 40 healthy men of similar age and body mass index.

RESULTS

Patients with chest pain had higher insulin responses to an intravenous glucose challenge, lower insulin sensitivity, lower high density lipoprotein (HDL) and subfraction 2 cholesterol, lower apolipoprotein AI, higher triglycerides, greater android fat and higher systolic blood pressure at rest compared with levels in healthy control subjects (p < 0.05). Those with an abnormal coronary angiogram had lower tissue plasminogen activator levels, higher plasminogen activator inhibitor 1 levels and more android fat than did those with a normal angiogram (p < 0.05). Insulin sensitivity correlated positively with HDL (p < 0.05) and subfraction 2 (p < 0.001) cholesterol and negatively with triglycerides (p < 0.01), android fat proportion (p < 0.01) and systolic blood pressure (p < 0.05), whereas insulin response showed converse correlations.

CONCLUSIONS

These findings provide new evidence of the central role of insulin resistance and hyperinsulinemia in the development of risk factors associated with coronary heart disease.

Early abnormalities in coronary heart disease risk factors in relatives of subjects with non-insulin-dependent diabetes

Coronary heart disease risk factor levels were studied in 184 first-degree relatives (sisters and brothers) of non-insulin-dependent diabetic subjects (124 relatives with normoglycemia, 34 relatives with impaired glucose tolerance [IGT], and 26 relatives with non-insulin-dependent diabetes mellitus [NIDDM]) and in 215 relatives of nondiabetic subjects (194 relatives with normoglycemia and 21 relatives with IGT). Subjects with IGT exhibited the highest insulin responses to an oral glucose load. Systolic blood pressure was significantly higher; serum high density lipoprotein cholesterol level was significantly lower; and total, low density lipoprotein, and very low density lipoprotein triglyceride levels were higher in the relatives with a family history of diabetes who had IGT or NIDDM than in the normoglycemic relatives without a family history of diabetes. These abnormal changes were not seen in normoglycemic relatives or relatives with IGT who had no family history of NIDDM. Thus, in relatives of diabetics, abnormal glucose tolerance seems to induce changes in cardiovascular heart disease risk factor levels that are similar to those observed in NIDDM. Therefore, a family history of diabetes adds substantially to the risk for atherosclerosis, particularly in subjects with IGT.

High density lipoprotein turnover in patients with hypertension

Although hyperinsulinemia and decreased high density lipoprotein cholesterol concentration can occur in patients with hypertension, there is no information available concerning the dynamic state of high density lipoprotein metabolism. To address this issue, we quantified high density lipoprotein turnover in 12 patients with mild hypertension and 11 matched subjects with normal blood pressure. Patients with high blood pressure had lower high density lipoprotein cholesterol concentrations. Fractional catabolic rates of 125I-apolipoprotein AI (apoAI)/high density lipoprotein were faster in patients with hypertension (0.36 +/- 0.02 versus 0.26 +/- 0.02 l/day, p less than 0.001). Total synthetic rates of apoAI were also significantly greater in patients with high blood pressure (17.4 +/- 1.1 versus 13.2 +/- 0.6 mg/kg/day, p less than 0.001). Although significant correlation was observed between blood pressure and fractional catabolic rate of 125I-apoAI/high density lipoprotein in the experimental population (r = 0.52, p less than 0.01), no relation was found when patients with normal blood pressure or hypertension were considered separately. However, a highly significant positive correlation was found between 125I-apoAI/high density lipoprotein fractional catabolic rate and insulin concentration in the entire population (r = 0.72, p less than 0.001). In conclusion, the patients with mild hypertension studied were hyperinsulinemic, had a faster fractional catabolic rate of 125I-apoAI/high density lipoprotein, and a lower high density lipoprotein-cholesterol concentration. It is suggested that the changes seen in high density lipoprotein-cholesterol concentration and 125I-apoAI/high density lipoprotein fractional catabolic rates were secondary to the hyperinsulinemia and not due to the high blood pressure per se.

Insulin resistance is associated with lipid and lipoprotein abnormalities in subjects with varying degrees of glucose tolerance

We tested the hypothesis that insulin resistance, rather than high insulin level, is associated with lipid and lipoprotein changes favoring atherosclerosis independently of the glucose tolerance status. To this aim, 50 subjects with normal glucose tolerance, 28 subjects with impaired glucose tolerance, and 54 subjects with noninsulin-dependent diabetes (NIDDM) were studied. Subjects with low glucose disposal rate (GDR) or a high degree of insulin resistance as measured by the euglycemic hyperinsulinemic clamp technique had lower high density lipoprotein (HDL) cholesterol and higher total and very low density lipoprotein (VLDL) triglycerides than did subjects with high GDR (highest GDR tertile). These associations were independent of fasting insulin level and other confounding factors. In stepwise multiple linear regression analysis, GDR was the most important single variable associated with HDL cholesterol and VLDL triglyceride level independently of age, obesity, distribution of obesity (waist/hip ratio), 2-hour glucose level, and free fatty acid concentration. We conclude: 1) insulin resistance measured by the euglycemic clamp technique is associated with adverse lipid and lipoprotein changes favoring atherosclerosis not only in nondiabetic subjects (as shown in previous studies) but also in impaired glucose tolerance and NIDDM subjects; 2) the association of high insulin level with adverse lipid and lipoprotein changes indirectly reflects the association of insulin resistance with lipid and lipoprotein levels; and 3) HDL cholesterol and VLDL triglycerides are independently associated with insulin-mediated glucose uptake, which may indicate that these lipoproteins have separate sites of interaction with insulin action.

Adverse effects of obesity on lipid and lipoprotein levels in insulin-dependent and non-insulin-dependent diabetes

We studied the association of obesity with lipid and lipoprotein concentrations in 92 patients (49 men, 43 women) with insulin-dependent diabetes (IDDM), in 305 patients (152 men, 153 women) with non-insulin-dependent diabetes (NIDDM), and in 122 nondiabetic control subjects (65 men, 57 women). Obesity (body mass index, BMI) was associated with abnormal lipid and lipoprotein levels only in the presence of diabetes, and lipid and lipoprotein changes were substantially more abnormal in patients with NIDDM than in patients with IDDM. In men and women with NIDDM, obesity was associated with low high-density lipoprotein (HDL) and HDL2 cholesterol and high total, low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) triglyceride concentrations. In men with IDDM, obesity was related only to low HDL and HDL2 cholesterol and in women with IDDM to low HDL3 cholesterol. BMI and diabetes status had a statistically significant interaction (analysis of variance) with respect to HDL and HDL2 cholesterol and total and VLDL triglycerides, indicating that the effects of obesity on lipids and lipoproteins were more severe in patients with diabetes than in nondiabetic subjects. In conclusion, obesity and diabetes status have an unfavorable interaction that results in multiple pathologic lipid and lipoprotein changes, particularly in NIDDM.

Asymptomatic hyperglycemia is associated with lipid and lipoprotein changes favoring atherosclerosis

We studied lipid and lipoprotein concentrations and their relationships to insulin level in 994 men and 1246 women ages 50 to 91 years in the upper middle-class community of Rancho Bernardo in southern California. Altogether, 593 men and 741 women had normal glucose tolerance, 240 men and 348 women, impaired glucose tolerance (IGT), 104 men and 117 women, newly diagnosed noninsulin-dependent diabetes (NIDDM), and 57 men and 40 women, previously diagnosed NIDDM. In women but not men, total cholesterol and low density lipoprotein were significantly higher in those with newly diagnosed NIDDM, compared to subjects with normal glucose tolerance. In both men and women, high density lipoprotein (HDL) cholesterol was significantly lower, and total triglyceride significantly higher, in subjects with IGT and NIDDM compared to those with normal glucose tolerance; these differences persisted after adjusting for age, body mass index, smoking, alcohol intake, and exercise level. Multiple linear-regression analyses showed that fasting insulin (but not 2-hour insulin) was significantly associated with low HDL cholesterol and high total triglycerides independently from other variables (age, body mass index, waist/hip ratio, alcohol intake, smoking, exercise, and 2-hour glucose). Overall, these results show that asymptomatic hyperglycemia (IGT, newly diagnosed NIDDM) is associated with lipid and lipoprotein changes favoring atherosclerosis and that fasting hyperinsulinemia (insulin resistance) is the most important factor associated with these lipid and lipoprotein abnormalities

Effect of prazosin treatment on carbohydrate and lipoprotein metabolism in patients with hypertension

This study evaluated the effect of prazosin in controlled mild hypertension and evaluated select metabolic changes that occurred with prazosin monotherapy. Various aspects of glucose, insulin, and lipid metabolism were studied before and after approximately 10 weeks of prazosin treatment in 12 patients with mild hypertension. Prazosin was well tolerated and induced a significant decrease (p less than 0.001) in both systolic and diastolic blood pressures, without any change in body weight. Plasma concentrations of glucose, free fatty acid, and lactate, which were measured hourly from 8 A.M. to 4 P.M. following meals consumed at 8 A.M. and noon, did not change with prazosin treatment. However, the plasma insulin response from 8 A.M. to 4 P.M. decreased significantly (p less than 0.001) following prazosin treatment. In addition, fasting plasma triglyceride and cholesterol concentrations were significantly lower (p less than 0.05) in prazosin-treated persons, as were postprandial triglyceride concentrations (p less than 0.001). Lower total plasma triglyceride and cholesterol concentrations were accounted for by decreases in very low-density lipoprotein cholesterol and triglyceride and low-density lipoprotein cholesterol and triglyceride, whereas both high-density lipoprotein triglyceride and high-density lipoprotein cholesterol concentrations increased following prazosin treatment. Finally, although both apolipoprotein A1 and apolipoprotein B concentrations decreased in association with prazosin treatment, the decrease in apolipoprotein B was much greater in magnitude, leading to an increase in the ratio of apolipoprotein A1 to apolipoprotein B. In this study, treatment of mild hypertension with prazosin led to lower blood pressures and changes in insulin and lipoprotein metabolism that are important in this patient population.

Macrovascular disease and hyperinsulinaemia

The evidence that hyperinsulinaemia represents an independent risk factor for cardiovascular disease is tantalizing but the hypothesis cannot be said to be proven. The inconsistencies arising from the major prospective studies require that further work be done. Hyperinsulinaemia may not carry the same implications in all subjects and its interactions with other risk factors and with blood glucose are not well described. Possible further research has been discussed and outlined at a recent meeting (Colwell, 1985). The suggestions include delineating the action of growth factors and insulin in defined serum-free tissue culture, and the use of more sophisticated culture models, such as smooth muscle covered by vascular endothelium. The choice of human or primate tissue is desirable because of the species specificity of the atherosclerotic lesions. Prospective trials of modifying peripheral insulin levels in treated diabetic patients are probably still impracticable. The case for attempting to achieve normoglycaemia in diabetes to avoid microvascular complications is strong, and current insulin treatment regimens accept peripheral hyperinsulinaemia as a consequence of achieving portal insulin concentrations sufficient to suppress hepatic glucose output. It is hard to envisage a trial to examine reduced peripheral insulin concentrations which would not give unacceptably poor blood glucose control. Current studies of different methods and degrees of control of blood glucose might be used to provide some indication of whether such a trial could ever be justified. The Diabetes Control and Complication Trial (DCCT) is a prospective multicentre study of intensive versus conventional insulin treatment in insulin-dependent diabetic patients in the USA, and the UK Prospective Study of therapies of maturity onset diabetes (UKPS) is following patients not satisfactorily controlled on diet, randomized to different treatment modalities. These may produce some evidence within the next few years, on insulin concentrations and complications (Tattersall and Scott, 1987). Should any of this change current management of non-insulin-dependent diabetes? Despite claims of enthusiasts, special treatment regimens with intensive exercise, a particular oral agent or the addition of sulphonylureas to insulin therapy are either not generally applicable or have little theoretical basis (Martin, 1986). Current 'good practice' in Europe as put forth in a consensus document (Alberti and Gries, 1988), recognizes the need to address risk factors other than diabetes in the management of the non-insulin-dependent diabetic patient.(ABSTRACT TRUNCATED AT 400 WORDS)

Association of serum lipids and lipoproteins with plasma C-peptide concentration in non-insulin-dependent diabetic and non-diabetic subjects

Serum lipids and lipoproteins were studied in 149 non-insulin-dependent diabetic subjects treated with diet or oral drugs (75 men, 74 women) and in 101 nondiabetic control subjects (49 men, 52 women) in relation to endogenous insulin secretion capacity measured by plasma C-peptide response to intravenous glucagon. Serum HDL- and HDL2-cholesterol concentrations were lower and VLDL-cholesterol and total and VLDL-triglyceride concentrations higher in subjects with high C-peptide response (above the median) than in subjects with low C-peptide response (lower or equal to median) both in diabetic and control subjects of both sexes. Adjustment for the effect of obesity abolished these differences in serum lipids and lipoproteins in diabetic subjects but not in control subjects. This may indicate that obesity has stronger influence on serum lipids in diabetic subjects than in nondiabetic subjects.

HDL metabolism in diabetes

Based on the data reviewed, it is necessary to conclude that diabetes is associated with profound changes in HDL metabolism. However, once we go beyond this simple generalization, it is apparent that the relationship between diabetes and HDL metabolism is not a simple one. A good deal of the complication evolves from the fact that IDDM and NIDDM seem to affect HDL metabolism quite differently, with the only apparent similarity the fact that plasma HDL-cholesterol concentration can be low in untreated patients with either IDDM or NIDDM. Thus, in patients with IDDM the primary event seems to be related to the insulin-deficient state, which results in a decrease in HDL turnover rate and resultant decline in plasma HDL-cholesterol concentration. In contrast, HDL turnover appears to be accelerated, not reduced in patients with NIDDM, and the low plasma HDL-cholesterol concentration is a consequence of the increased turnover rate. In addition, patients with NIDDM are not absolutely insulin deficient, and available evidence suggests that the higher the plasma insulin level, the lower the plasma HDL-cholesterol concentration in these patients. The differences noted above in the effect of IDDM and NIDDM on HDL metabolism are of great interest, and, unfortunately, not very well understood. There is, however, one additional difference, which may be of paramount clinical importance. For reasons not totally clear, plasma HDL-cholesterol concentrations in patients with IDDM treated with insulin are not lower than normal, and even tend to be higher than these values in a nondiabetic population. Possibly as a result of this phenomenon, there is no evidence that changes in plasma HDL-cholesterol concentration play a role in the development of macrovascular complications in IDDM. Although it is apparent from the considerations discussed in this review that a great deal more needs to be learned about the effect of insulin deficiency on HDL metabolism, changes in HDL metabolism do not appear to be clinically important in patients with IDDM. Unfortunately, this does not appear to be the situation in patients with NIDDM. Plasma HDL-cholesterol concentrations are lower than normal in patients with NIDDM, and this finding seems to be related to increased morbidity and mortality from CAD. Furthermore, there is no form of anti-diabetic treatment, irrespective of how effective it has been in achieving glycemic control, that has been shown to substantially increase plasma HDL-cholesterol level. Indeed, it has been difficult to demonstrate a consistent effect of any therapeutic approach on plasma HDL-cholesterol concentration.(ABSTRACT TRUNCATED AT 400 WORDS)

Evidence for an independent relationship between plasma insulin and concentration of high density lipoprotein cholesterol and triglyceride

Increased plasma insulin and triglycerides and decreased high density lipoprotein concentrations are primary risk factors in the development of coronary artery disease. The aim of the present study was to verify whether there was an independent relationship between plasma insulin levels and both HDL cholesterol and triglyceride in a worker population of 607 subjects, 389 men and 218 women, aged 23-73 years. An oral glucose tolerance test (75 g) was performed. Plasma glucose, insulin, triglyceride and HDL cholesterol were measured at fasting, plasma glucose and insulin were determined also 1 h and 2 h after glucose load. The results, examined separately in men and women documented a significant negative relationship between plasma insulin and HDL cholesterol level, as well as pointing out that both HDL cholesterol and insulin are significantly correlated to degree of hypertriglyceridemia, degree of obesity and level of glucose tolerance. The partial correlation coefficients between HDL cholesterol and plasma insulin levels at fasting in men and post-glucose load in women, demonstrated an independent relationship between increased plasma insulin and decreased plasma HDL concentration. However, the strongest relationship, revealed by partial correlation coefficient analysis, was between the degree of hyperinsulinemia and hypertriglyceridemia.

Hyperlipemia and arteriosclerotic cardiovascular disease in the Polynesian population of Rarotonga

Total cholesterol, total triglyceride and high density lipoprotein (HDL) cholesterol and their relation to arteriosclerotic cardiovascular disease (ASCVD) were investigated in a population of Polynesian Maoris in Rarotonga who are becoming increasingly westernized. 8.5% of the population had plasma triglyceride elevations (triglyceride greater than or equal to 200 mg/dl), and the occurrence of hypertriglyceridemia was significantly higher in males than females. 5.8% of the population had elevations of total cholesterol (cholesterol greater than or equal to 250 mg/dl), and the proportion with elevation of total cholesterol was similar for males and females. 3.2% of the population had elevations of both triglyceride and cholesterol. HDL cholesterol concentrations were relatively low, and no sex differences were observed at any age. Analysis of lipoprotein cholesterol and triglyceride in a subset of those who had hyperlipemia indicated that the elevations of total cholesterol and triglyceride were mainly due to elevations of low density lipoprotein (LDL) cholesterol and very low density lipoprotein (VLDL) triglyceride, respectively; furthermore, elevations of VLDL triglyceride and LDL cholesterol were significantly correlated with increase in VLDL apolipoprotein B (apo B) and LDL apo B, respectively. Although an appreciable prevalence of diabetes was observed in this population (male: 6.7%, female: 8.4%), the diabetes could not account for the hyperlipemia. Among 693 subjects between the ages of 30 and 59 years, approx. 3% of males and 1% of females had Q-wave changes, and 16% of females and 4% of males had ST-T changes. Among males with Q-wave abnormalities, hyperlipemia was more frequent. There was also increased frequency of hypertension in those with elevated lipids. The data indicate the occurrence of some hyperlipemia in this population which could be of the familial-combined type; the elevated plasma lipids may contribute to the increased frequency of coronary heart disease.

Effect of weight loss in moderate obesity on plasma lipoprotein and apolipoprotein levels and on high density lipoprotein composition

Plasma lipids, lipoprotein and apolipoprotein levels were determined in seven women and seven men with moderate obesity before, during 7 weeks of continuous weight loss (10.4% to 9.6% of body weight, 1000 kCal/day diet), and after 3 months at a stable, reduced weight. Plasma triglyceride levels decreased by 30.4% in men and by 39.4% in women (p less than 0.0001) after 1 week of caloric restriction and remained at this level throughout the study period. The plasma cholesterol decreased by 19.0% in men (p less than 0.001) and by 10.9% in women (p less than 0.01) in the period of active weight loss, but returned to prediet values after stabilization at a leaner body mass. Similar changes were observed in LDL cholesterol levels. No change in high density lipoprotein (HDL) cholesterol levels occurred during active weight reduction, but after 3 months at a reduced weight, a significant increase in HDL cholesterol was evident, and the ratio of HDL cholesterol to plasma cholesterol increased over prediet values (p less than 0.001), women). Separation of HDL subpopulations by zonal ultracentrifugation before and after weight reduction revealed that HDL2 increased slightly in men and decreased slightly in women. In both genders, HDL3 tended to decrease after weight reduction. Plasma levels of apolipoprotein A-I decreased during active weight loss, but this was significant only in women (p less than 0.05). After 3 months of reduced weight, plasma apo A-I increased to prediet levels. No significant changes in plasma apo A-II or apo E were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum triglycerides, cholesterol, low density lipoprotein-apo B and high density lipoprotein cholesterol subfractions after moderate body weight loss

Low calorie diet (4.18 MJ daily) was given to 48 (35 female, 13 male) obese patients during 24 days followed by 7 days of normal diet (9.61 MJ daily). Patients were treated in sanatorium under steady medical control. The average body weight decrease in women was 5.3 kg and in men 6.2 kg. A significant decrease in serum triglycerides, total cholesterol and apolipoprotein B in low density lipoproteins (LDL-apo B) was observed after low calorie diet. No influence on high density lipoprotein cholesterol (HDL-chol), HDL2-chol and HDL3-chol in men and on HDL3-chol in women was observed. The HDL2-chol decreased in women. The LDL-apo B/HDL-chol ratio decreased in both sexes, however, it was significant only in women. After 7 days of normal diet no further significant changes in serum lipids and lipoproteins were observed.

High density lipoprotein apoprotein variability in a biracial population

High density lipoprotein (HDL) cholesterol is a sensitive index for coronary disease in affluent societies. We have measured plasma apoprotein A-I levels (the major HDL protein) in randomly selected groups of urban and rural Fijian Melanesians and Indians. Despite higher prevalence rates of coronary disease and diabetes mellitus in Indians, Indian men and women had significantly higher A-I levels than Melanesian men and women. Multivariate analysis was carried out separately in all men and women of both races and also in younger men and women (less than 45 years old) to determine the predictive values of seven variables that might influence A-I levels. These variables accounted for about 16% of the A-I variation and of this more than one-half was due to ethnic origin. The remainder was largely due to three environmental factors: urbanization, alcohol consumption, and physical activity. Men and women aged 20 to 44 years had significantly higher A-I levels in the town than in villages; alcohol drinkers had significantly higher A-I levels than nondrinkers, and in women physical inactivity resulted in significantly lower A-I levels. Age, smoking cigarettes, and body mass index did not contribute to the differences in A-I levels between the two races, despite less smoking and overweight among Indians. This study of a biracial population, that shares a similar environment but differs in cultural habits, has demonstrated the operation of genetic and environmental factors that explain a minor proportion of apoprotein A-I variability.

High-density lipoprotein-cholesterol and diet in a healthy elderly population

This study examined how high-density lipoprotein-cholesterol (HDL-C) correlated with a 3-day food record of fat, protein, carbohydrate, and alcohol consumption in a group of 270 healthy subjects over age 60. HDL-C concentrations correlated with alcohol consumption (expressed as grams/day) (r = + .25, P less than .001), and inversely with total carbohydrate (r = - .18, P less than .01) and refined carbohydrate (r = - .17, P less than .01) ingestion (expressed as a percent of total caloric intake). Subjects consuming diets low in either total carbohydrate or refined carbohydrate had 10 to 20% higher HDL-C levels than did those consuming diets high in these food substances. The relationships between HDL-C levels and alcohol and carbohydrate ingestion were independent of other variables which correlated with HDL-C levels. Dietary fat (total fat, saturated fat, unsaturated fat, and cholesterol) did not correlate with HDL-C. LDL-cholesterol and triglyceride levels did not correlate with any dietary variable measured.