Physical activity and incidence of diabetes: the Honolulu Heart Program

Plasma lipoproteins and incidence of non-insulin-dependent diabetes mellitus in Pima Indians: protective effect of HDL cholesterol in women

The role of plasma lipoproteins in the development of non-insulin-dependent diabetes mellitus (NIDDM) was studied in 787 non-diabetic (2-h glucose < 11.1 mmol/l) Pima Indians (265 men and 522 women). Subjects were followed for a mean of 9.8 (range: 1.8-16.4) years, during which 261 (76 men and 185 women) developed NIDDM. In men and women, very-low-density lipoprotein (VLDL) cholesterol, VLDL triglyceride, low-density lipoprotein triglyceride and total triglyceride, controlled for age, predicted NIDDM (P < 0.01 for each). These effects diminished when controlled for age, sex, body mass index, systolic blood pressure and 2-h glucose. However, high-density lipoprotein (HDL) cholesterol, controlled for age, body mass index, systolic blood pressure and 2-h glucose, was a significant protective factor for NIDDM in women (hazard rate ratio (HRR) = 0.35, 95% CI (0.23-0.54), P < 0.001, 90th compared with 10th percentile) but not in men (HRR = 1.04, 95% CI (0.53-2.05), P = 0.915). This association remained significant in women when controlled for fasting or 2-h plasma insulin concentrations, other estimates of insulin resistance or alcohol consumption. The protective effect of HDL cholesterol was similar among women with normal (2-h glucose < 7.8 mmol/1) or impaired (7.8 mmol/l < or = 2-h glucose < 11.1 mmol/l) glucose tolerance at baseline. These results indicate that lipoprotein disorders are an early accompaniment of the abnormalities that lead to NIDDM.

Distribution and correlates of lipids and lipoproteins in elderly Japanese-American men. The Honolulu Heart Program

Adverse lipid and lipoprotein levels are clearly linked with increased risk of cardiovascular disease in middle age, but evidence in elderly and minority populations is less certain. In this study the distribution and correlates of lipids and lipoproteins were evaluated cross-sectionally in 3044 elderly (71 to 93 years) Japanese-American men from the Honolulu Heart Program who were recently reexamined (1991 to 1993). Mean +/- SD lipid concentrations were 189 +/- 33 mg/dL for total cholesterol, 51 +/- 13 mg/dL for HDL cholesterol, 109 +/- 31 mg/dL for LDL cholesterol, and 147 +/- 89 mg/dL for triglycerides. Prevalence of dyslipidemic patterns was relatively infrequent (total cholesterol > or = 240 mg/dL: 6.7%; HDL cholesterol < 35 mg/dL, 6.4%; LDL cholesterol > or = 160 mg/dL: 5.5%; triglycerides > or = 200 mg/dL. 18.7%), while prevalence of desirable total (< 200 mg/dL) and HDL cholesterol (> or = 60 mg/dL) concentrations was more common (62.7% and 23.7%, respectively). Mean levels of total cholesterol, LDL cholesterol, and triglyceride decreased significantly with increasing age (P < .001), while mean HDL cholesterol level increased slightly (P < .05). After univariate analyses of potential correlates, multiple linear regression models were used to identify variables independently associated with each of the lipids. After adjustment for other variables, levels of fibrinogen and hematocrit were positively associated and insulin, white blood cell count, and use of diabetic medication were negatively associated with total cholesterol. Correlates for LDL cholesterol were similar but also included vital capacity (positive relation) and alcohol (negative relation). Heart rate, physical activity, alcohol, and hematocrit were positively associated with HDL cholesterol; body mass index, subscapular skinfold thickness, glucose, fibrinogen, white blood cell count, and hypertension were negatively associated. Factors associated with triglycerides tended to be similar, yet the direction of relations was reversed. Age-adjusted total cholesterol levels were significantly lower in men who had coronary surgery, thromboembolic stroke, and hemorrhagic stroke but were higher in those with peripheral vascular disease. Lower HDL cholesterol levels were found in men with prevalent angina, angioplasty, definite myocardial infarction, thromboembolic stroke, and peripheral vascular disease. LDL cholesterol and triglycerides showed fewer significant relations with these conditions. Findings indicate that elderly Japanese-American men have a favorable lipid profile, except for elevated triglyceride levels, relative to levels in other populations of older Americans and that a number of cardiovascular risk factors and diseases are strongly associated with lipids in elderly men. These analyses also identify several modifiable factors that may favorably influence lipid and lipoprotein levels in the elderly.

Baseline dietary intake and physical activity of Japanese American men in relation to glucose tolerance at 5-year follow-up

Japanese American men (n = 124), with normal glucose tolerance (NGT, n = 69) or impaired glucose tolerance (IGT, n = 55) at baseline, were studied for effects of baseline dietary intake and physical activity on glucose tolerance at baseline and at 5-year follow-up. At baseline, both NGT and IGT men with positive family history of diabetes (FH) showed high intakes of animal fat and protein, but only the NGT men countered this with high levels of energy expenditure. In the total sample at 5-year follow-up, 2-hour plasma glucose was significantly related to intake of animal fat (AF), partial correlation r = 0.32, P < 0.001, adjusted for total energy intake, age, self-reported health, body mass index, FH, and baseline glucose tolerance category. Energy expenditure (EE) was not related to 5-year 2-hour plasma glucose in the total sample, but displayed a relationship with 5-year 2-hour plasma glucose in those IGT (r = -0.27, P < 0.05), but not in those NGT at baseline, and in those with positive FH (r = -0.33, P < 0.05), but not in those with negative FH. Additionally, AF showed a relationship to 5-year 2-hour plasma glucose only for those in the lowest (r = 0.37, P < 0.05) and middle (r = 0.33, P < 0.05) tertiles, but not in the highest tertile of EE. For baseline IGT men, 5-year 2-hour plasma glucose was related to "high vs. low risk" categories of AF intake and EE, but only in men with a positive FH (AF ≥ 25 vs. < 25 g/day: 180.1 ± 38.6 vs. 143.6 ± 39.7 mg/dl, P = 0.048; EE ≤ 2,000 kcal/week vs. > 2,000 kcal/week, 189.9 ± 39.2 vs. 150.8 ± 37.4 mg/dl, P = 0.028; with risk categories combined, i.e., both high, mixed, both low: 192.0 ± 41.3, 165.4 ± 28.4, 139.4 ± 40.9 mg/dl, P = 0.045, linear trend, P = 0.014). Thus, high AF intake and low EE may have long-range detrimental effects on glucose tolerance, especially for those with IGT and positive FH. © 1996 Wiley-Liss, Inc.

Distribution and correlates of insulin in elderly men. The Honolulu Heart Program

The role of insulin in cardiovascular disease is uncertain, and studies in elderly or minority populations are infrequent. Fasting and 2-hour insulin concentrations and their cross-sectional associations with cardiovascular risk factors were examined in 3562 elderly (aged 71 to 93 years) Japanese American men from the Honolulu Heart Program who were reexamined between 1991 and 1993. Insulin distributions were skewed (mean and median: 16.8 and 12 microU/mL for fasting; 117.2 and 93 microU/mL for 2-hour); fasting but not 2-hour insulin levels declined significantly with age (P < .0001 and P = .54, respectively). Factors most strongly correlated with insulin included measures of obesity, fat distribution, and levels of triglyceride, glucose (r = .38 to r = .50 fasting, r = .21 to r = .27 2-hour), and HDL cholesterol (r = -.41 and r = -.22, respectively). Other correlates included fibrinogen, hematocrit, heart rate, blood pressure, cigarettes per day (all positive), alcohol, physical activity, and forced vital capacity (negative). Associations were also evident across risk factor quintiles. Insulin levels were significantly elevated in men with hypertension and diabetes. In multiple linear regression analyses, log10 fasting insulin was positively and independently associated with body mass index, triglycerides, glucose, fibrinogen, hematocrit, heart rate, diabetes, and hypertension and negatively associated with HDL cholesterol, physical activity, and forced vital capacity. In general, results were similar for log10 2-hour insulin and when subjects who fasted < 12 hours or had diabetes were excluded. Substitution of medication use and blood pressure for hypertension indicated independent associations of medication use but not blood pressure with insulin.(ABSTRACT TRUNCATED AT 250 WORDS)

Internal validity of the physical activity index over 26 years in middle-aged and older men

OBJECTIVE

To determine the internal validity of the physical activity index (PAI).

DESIGN

Three time periods over a 26-year period (1965/68 examination, n = 7911; 1980/82 examination, n = 2054; 1991/93 examination, n = 3425).

SETTING

Honolulu, Hawaii.

PARTICIPANTS

Middle-aged to older Japanese-American men.

MEASUREMENTS

PAI, other physical activity measures, body mass index (BMI), tricep skinfold thickness, subscapular skinfold thickness, and HDL cholesterol.

RESULTS

PAI levels was associated significantly with levels of other physical activity measures at all time periods. Higher PAI level was associated with lower BMI at the baseline examination (1965/68), lower subscapular skinfold thickness at the 1965/68 and 1980/82 examinations, lower tricep skinfold thickness at all examinations, and higher HDL cholesterol at the 1980/82 examination. Change in PAI level from 1965/68 to 1980/82 was associated with change in BMI, subscapular, and tricep skinfold thickness levels, but there were no significant associations between change in PAI level and change in BMI, skinfold thicknesses, or HDL cholesterol levels from 1980/82 to 1991/93.

CONCLUSION

PAI level is a relatively valid estimate of overall daily energy expenditure that may be an acceptable general measure across the middle-to-late stages of life. The PAI may also be sensitive enough to discern a shift toward less physical demanding activities as a population becomes older, although further studies should be conducted to better determine its validity in older populations.