Dimensional analysis of actigraphic derived sleep data.

Nonlinear dimensional analyses can be a useful tool in understanding the underlying behavior of dynamical systems, including biological systems. Many biological functions can be modeled as chaotic processes, including sleep. Sleep data can be obtained from several methods, such as electroencephalograms, polysomnography, and actigraph. Actigraphy, because of its low level of invasiveness, is an increasingly popular method of obtaining sleep data. This study analyzed actigraphy data with nonlinear dimensional analyses to determine if such analytic methods would be useful in sleep studies. Participants wore actigraphs on their wrists, which recorded movement for several days. Several sleep quality variables, such as movement during sleep and total sleep time, were derived from these sleep data. These variables were used to determine whether the quality of sleep was good or poor. Lagged phase space plots were graphed and nonlinear parameters for the fractal dimension and the correlation dimension were computed for each participant. Descriptive and inferential statistics were performed to determine if the nonlinear parameters showed significant differences with respect to sleep quality.

Estimation of the maximum flow-mediated brachial artery response using local regression methods.

We consider methods for estimating the maximum from a sequence of measurements of flow-mediated diameter of the brachial artery. Flow-mediated vasodilation (FMD) is represented using the maximum change from a baseline diameter measurement after the release of a blood pressure cuff that has been inflated to reduce flow in the brachial artery. The influence of the measurement error on the maximum diameter from raw data can lead to overestimation of the average maximum change from the baseline for a sample of individuals. Nonparametric regression models provide a potential means for dealing with this problem. When using this approach, it is necessary to make a judicious choice of regression methods and smoothing parameters to avoid overestimation or underestimation of FMD. This study presents results from simulation studies using kernel-based local linear regression methods that characterize the relationship between the measurement error, smoothing and bias in estimates of FMD. Comparisons between fixed or constant smoothing and automated smoothing parameter selection using the generalized cross validation (GCV) statistic are made, and it is shown that GCV-optimized smoothing may over-smooth or under-smooth depending on the heart rate, measurement error and measurement frequency. We also present an example using measured data from the Buffalo Cardio-Metabolic Occupational Police Stress (BCOPS) pilot study. In this example, smoothing resulted in lower estimates of FMD and there was no clear evidence of an optimal smoothing level. The choice to use smoothing and the appropriate smoothing level to use may depend on the application.

Occupational and other risk factors for hand-grip strength: the Honolulu-Asia Aging Study.

BACKGROUND: In certain occupations, including farm work, workers are exposed to hazardous substances, some of which are known to be toxic to the nervous system and may adversely affect muscle strength. Measurement of hand-grip strength may be useful for detecting neurotoxic exposure. METHODS: The authors studied 3522 participants of the Honolulu Heart Program and the Honolulu-Asia Aging Study to determine whether occupational exposures to pesticides, solvents, and metals assessed at exam I (1965-68) are associated with hand-grip strength at exam IV (1991-93) and change in hand-grip strength over 25 years. Correlation, analysis of variance and covariance, and linear regression were used to evaluate the associations. RESULTS: At exam IV, participants ranged in age from 71-93 years; mean hand-grip strength was 39.6 kg at exam I and 30.3 kg at exam IV. Over 25 years, the decline in hand-grip strength was an average of 8-9 kg for all exposures. Hand-grip strength was inversely associated with age and glucose but directly associated with cognitive function, BMI, and haemoglobin level. No other exposures were associated with hand-grip strength. CONCLUSION: This study did not provide evidence that occupational exposure to pesticides, solvents, and metals adversely affected hand-grip strength in this population, but confirmed other important associations with hand-grip strength.

A statistical test to determine the quality of accelerometer data.

Accelerometer data quality can be inadequate due to data corruption or to non-compliance of the subject with regard to study protocols. We propose a simple statistical test to determine if accelerometer data are of good quality and can be used for analysis or if the data are of poor quality and should be discarded. We tested several data evaluation methods using a group of 105 subjects who wore Motionlogger actigraphs (Ambulatory Monitoring, Inc.) over a 15 day period to assess sleep quality in a study of health outcomes associated with stress among police officers. Using leave-one-out cross-validation and calibration-testing methods of discrimination statistics, error rates for the methods ranged from 0.0167 to 0.4046. We found that the best method was to use the overall average distance between consecutive time points and the overall average mean amplitude of consecutive time points. These values gave us a classification error rate of 0.0167. The average distance between points is a measure of smoothness in the data, and the average mean amplitude between points gave an average reading. Both of these values were then normed to determine a final statistic, K, which was then compared to a cut-off value, K(C), to determine data quality.

Left atrial dimension and risk of systemic embolism in patients with a prosthetic heart valve. Department of Veterans Affairs Cooperative Study on Valvular Heart Disease.

The relation between left atrial dimension measured by M-mode echocardiography and systemic embolization after valve replacement was examined prospectively among 397 patients with a prosthetic valve enrolled in the Department of Veterans Affairs Cooperative Study on Valvular Heart Disease. Baseline characteristics including several measures of left atrial enlargement were compared for 31 patients who developed systemic embolism and 366 who did not develop embolism during a 5 year follow-up period. Variables that were significantly related to left atrial dimension or systemic embolization in univariate analyses were included with several others in a multiple logistic regression model. The incidence rate of systemic embolism was more than three times higher after mitral valve replacement than after aortic valve replacement (4.4 and 1.3 per 100 patient-years, respectively); this difference persisted after adjustment for other factors. Univariate analysis indicated a threefold higher incidence of systemic embolism in patients with a left atrial dimension greater than or equal to 4 cm compared with that in patients with a dimension less than 4 cm (3 versus 1 per 100 patient-years, respectively). However, when the effect of valve location (mitral versus aortic) was taken into account using either univariate or multivariate techniques, left atrial dimension was found not to be associated with systemic embolism. In multivariate analysis, atrial fibrillation, age, ejection fraction and location of the prosthetic valve were significantly associated with embolism. Results of this multicenter study suggest that left atrial dimension is not independently related to the development of systemic embolism in patients undergoing valve replacement.

Comparison of outcome after valve replacement with a bioprosthesis versus a mechanical prosthesis: initial 5 year results of a randomized trial.

The Veterans Administration Cooperative Study on Valvular Heart Disease was organized to compare survival and incidence of valve-related complications between patients receiving a bioprosthesis (the Hancock porcine heterograft) and a mechanical prosthesis (the Björk-Shiley spherical disc valve). Five hundred seventy-five patients undergoing single aortic or mitral valve replacement were randomized at surgery to one of the two valve types. At an average follow-up of 5 years (range 3 to 8) there are no statistically significant differences in survival between patients with the two valve types in the aortic valve replacement group. There is a statistically nonsignificant trend toward improved survival in patients undergoing mitral valve replacement with a bioprosthesis compared with a mechanical prosthesis (5 year survival probability was 0.70 +/- 0.05 and 0.58 +/- 0.06, respectively). Fatal and nonfatal valve-related complications occurred significantly less frequently in patients with a bioprosthesis compared with a mechanical prosthesis for both mitral and aortic valve replacement. Five year complication-free probability was 0.67 +/- 0.05 and 0.45 +/- 0.06, respectively, for patients with mitral valve replacement and 0.63 +/- 0.04 and 0.53 +/- 0.04, respectively, for those with aortic valve replacement. The difference in overall complication rates was largely due to the increased number of clinically significant but nonfatal bleeding episodes in patients receiving a mechanical prosthesis. Adjustment for differences in baseline characteristics between patients receiving a mitral mechanical prosthesis and a mitral bioprosthesis reduced the statistical significance of the difference in both mortality and complications.

Metabolic cardiovascular syndrome and risk of dementia in Japanese-American elderly men. The Honolulu-Asia aging study.

Cardiovascular risk factors often cluster into a metabolic syndrome that may increase the risk of dementia. The objective of the present study was to assess the long-term association between clustered metabolic cardiovascular risk factors measured at middle age and the risk of dementia in old age. This prospective cohort study of cardiovascular disease was started in 1965 and was extended to a study of dementia in 1991. The subjects were Japanese-American men with an average age of 52.7+/-4.7 (mean+/-SD) years at baseline. Dementia was diagnosed in 215 men, according to international criteria, and was based on a clinical examination, neuropsychological testing, and an informant interview. The z scores were calculated for 7 risk factors (random postload glucose, diastolic and systolic blood pressures, body mass index, subscapular skinfold thickness, random triglycerides, and total cholesterol). The relative risk (RR [95% CI]) of dementia (subtypes) per 1 SD increase in the sum of the z scores was assessed after adjustment for age, education, occupation, alcohol consumption, cigarette smoking, and years of childhood lived in Japan. The z-score sum was higher in demented subjects than in nondemented subjects, indicating a higher risk factor burden (0.74 versus -0.06, respectively; P=0. 008). Per SD increase in the z-score sum, the risk of dementia was increased by 5% (RR 1.05, 95% CI 1.02 to 1.09). The z-score sum was specifically associated with vascular dementia (RR 1.11, 95% CI 1.05 to 1.18) but not with Alzheimer's disease (RR 1.00, 95% CI 0.94 to 1.05). Clustering of metabolic cardiovascular risk factors increases the risk of dementia (mainly, dementia of vascular origin).

Lifestyle and biologic factors associated with atherosclerotic disease in middle-aged men. 20-year findings from the Honolulu Heart Program.

OBJECTIVES: To examine the association between a variety of baseline lifestyle and biologic factors in a middle-aged cohort of Japanese-American men and the 20-year incidence rates of total atherosclerotic end points and each of the initial clinical manifestations of this disease, including fatal and nonfatal coronary heart disease, angina pectoris, thromboembolic strokes, and aortic aneurysms. DESIGN: Prospective epidemiologic study. POPULATION: Japanese-American men (N = 2710) between the ages of 55 and 64 years at the time of the initial clinical examination of the Honolulu Heart Program (1965 through 1968) free from evidence of coronary heart disease, cerebrovascular disease, cancer, or aortic aneurysms. RESULTS: Among the men studied, 602 atherosclerotic events developed during the 23-year period of follow-up (1965 through 1988). After adjustment for each of the baseline characteristics examined, significant positive associations between quartile cutoffs of body mass index, systolic blood pressure, serum levels of cholesterol, triglycerides, glucose, and uric acid, as well as cigarette smoking, and the occurrence of any atherosclerotic end point were seen, while an inverse association with alcohol consumption was observed. Characteristics associated with the development of other fatal and nonfatal clinical events in this cohort, including coronary heart disease, thromboembolic stroke, and aortic aneurysms are presented with accompanying relative and attributable risks. CONCLUSIONS: The results of this prospective epidemiologic study provide insights to the long-term predictive utility of the commonly accepted risk factors for coronary heart disease in relation to the different clinical manifestations of atherosclerosis in a middle-aged male cohort followed up for approximately 20 years. These results provide additional support for risk factor modification in middle-aged men and for the encouragement of positive long-term lifestyle changes.

Serum cholesterol level and mortality due to suicide and trauma in the Honolulu Heart Program.

BACKGROUND: Recent results from cholesterol level-lowering trials and some, but not all, observational studies support an intriguing link between low or lowered serum cholesterol levels and violent death. The reasons behind this relationship are far from clear. METHODS: In this report, we further investigate this issue by assessing the relationship of baseline serum cholesterol levels with long-term risk of mortality due to trauma and suicide in a cohort of 7309 middle-aged Japanese-American men. RESULTS: After 23 years of follow-up, a total of 75 traumatic fatalities and 24 deaths by suicide were documented. Rather than an inverse relation, a positive association between serum cholesterol level and risk of suicide death was observed. After controlling for potential confounders, the relative risk of suicide associated with an increment of 0.98 mmol/L (38 mg/dL) in serum cholesterol level (1 SD) was 1.46 (95% confidence interval, 1.04 to 2.05; P = .02). Multivariate analysis of traumatic mortality failed to detect a relation with serum cholesterol level (relative risk = 0.89; 95% confidence interval, 0.70 to 1.13; P = .44). Heavy alcohol consumption (> 1200 mL of alcohol per month, top quintile) was an independent risk factor for trauma death relative to abstinence (relative risk = 1.86; 95% confidence interval, 1.07 to 3.22; P = .02). CONCLUSIONS: These findings contradict the hypothesis of an inverse relation between serum cholesterol level and suicide, but they support the hypothesis that heavy alcohol consumption is a risk factor for traumatic fatal events.

Glucose intolerance and 23-year risk of coronary heart disease and total mortality: the Honolulu Heart Program.

OBJECTIVE: The associations between glucose intolerance measured at the study entry date and the 23-year incidence of coronary heart disease (CHD), CHD mortality, and total mortality were examined at the Honolulu Heart Program. RESEARCH DESIGN AND METHODS: This prospective study followed a cohort of 8,006 Japanese-American men who were 45-68 years old and living on the island of Oahu, HI, in 1965. Baseline glucose was measured in a nonfasting state 1 h after a 50-g glucose load. History and use of medication for diabetes was obtained during an interview. The cohort was divided into four categories of glucose tolerance: low-normal, high-normal, asymptomatic hyperglycemia, and known diabetes. RESULTS: During the 23 years of follow-up, 864 incident cases of CHD, 384 deaths from CHD, and 2,166 total deaths occurred. The relative risks (RRs) were obtained using Cox proportional hazards modeling, with the low-normal category as a reference. The RRs were adjusted for age only, as well as for age, BMI, hypertension, cholesterol, triglycerides, smoking, alcohol, and a Japanese diet index. The age-adjusted and risk factor-adjusted RRs for all outcomes were significant for the asymptomatic hyperglycemic and known diabetes groups (P<0.05). The age-adjusted RRs for CHD incidence and total mortality were marginally significant in the high-normal group, but the RRs were not significant when adjusted for risk factors. CONCLUSIONS: These results suggest a dose-response relation of glucose intolerance at baseline with CHD incidence, CHD mortality, and total mortality, independent of other risk factors, in this cohort of middle-aged and older Japanese-American men.

Impaired glucose tolerance, diabetes, and cardiovascular disease risk factor profiles in the elderly. The Honolulu Heart Program.

OBJECTIVE: The relationship between glucose tolerance status and other cardiovascular disease (CVD) risk factors was evaluated in a cohort of Japanese-American men (n = 3,741) ages 71-93 years who participated in the fourth examination of the Honolulu Heart Program in 1991-1993. RESEARCH DESIGN AND METHODS: In this cross-sectional study, subjects were classified by reported diabetes and glucose tolerance status using questionnaires and the World Health Organization (WHO) criteria, respectively. RESULTS: The prevalence of reported diabetes was 17%. Among the men who completed an oral glucose tolerance test and had no history of diabetes (n = 1,900), 23% were diagnosed as diabetic and 39% had impaired glucose tolerance (IGT) by WHO criteria. The CVD risk factor profiles of men with IGT and diabetes were significantly more adverse compared with men with normal glucose tolerance after adjustment for age. The rates of hypertension, mean levels of BMI, waist-to-hip ratio, triglycerides, and fasting insulin were higher in men with IGT and diabetes compared with normal subjects. Opposite trends were observed for HDL cholesterol. Two-hour insulin was significantly higher among men with IGT and previously undiagnosed diabetes. Men with known diabetes had a lower physical activity index and higher fibrinogen levels than normal subjects. No significant differences were observed for current smoking and alcohol intake. Differences in risk factor levels by glucose tolerance status remained after adjustment for age, physical activity, BMI, and waist-to-hip ratio. CONCLUSIONS: These findings show that among elderly men of Japanese ancestry, impaired glucose tolerance and undiagnosed and known diabetes are highly prevalent, and these conditions are associated with adverse CVD factor profiles.

Increased incidence and prevalence of multiple sclerosis in Los Alamos County, New Mexico.

The incidence and prevalence of multiple sclerosis (MS) in Los Alamos County, New Mexico, were investigated because the number of reported cases appeared to have increased. The point prevalence on November 1, 1979, was 75.7 per 100,000, and average annual incidence rates for the period 1960-1969 and 1970-1979 were 3.4 and 3.7 per 100,000, respectively. The rates of MS in Los Alamos County were greater than expected from previous epidemiologic surveys of North America. The unusual ethnic composition and high socioeconomic level of the population probably contributed to the increases.

Changes in total and high-density lipoprotein cholesterol over 10- and 20-year periods (the Honolulu Heart Program).

Limited data are available on patterns of change in lipids and lipoproteins as persons age. The purpose of this report is to describe the 10-year change in total and high-density lipoprotein (HDL) cholesterol according to suspected determinants in 898 Japanese-American men enrolled in the Honolulu Heart Program. Data are based on examinations that occurred from 1970 to 1972 and at repeat examinations received 10 and 20 years later. At the last examination, men were aged 71 to 93 years. Mean reductions in total cholesterol in the second 10 years of follow-up (24 mg/dl) were more than double the reductions observed in the first 10 years (9 mg/dl). Levels of total cholesterol declined and levels of HDL cholesterol increased regardless of beginning levels of systolic blood pressure, body mass index, physical activity, cigarette smoking status, or the use of treatment for hypertension or elevated total cholesterol. Men with prevalent coronary heart disease experienced greater reductions (p <0.05) in total cholesterol during the second 10 years of follow-up (32 mg/dl) versus men without coronary heart disease (22 mg/dl). Adjustment for baseline covariates failed to alter these findings appreciably. We conclude that alterations in total and HDL cholesterol with advancing age may be expected to occur regardless of risk factor status, disease prevalence, or pharmacologic intervention. In the presence of such effects, evaluation of treatment programs to alter levels of total and HDL cholesterol in older persons should consider the possibility that even in the absence of intervention, changes could also occur due to aging alone.

Influence of myocardial infarction, coronary artery bypass surgery, and stroke on cognitive impairment in late life.

Relations between cognitive test scores in later life and prior myocardial infarction (MI), coronary artery bypass graft surgery (CABG), and stroke were examined for this study. Subjects were 3,734 Japanese-American men (80% of surviving Honolulu Heart Program cohort) aged 71 to 93 years at the time of cognitive testing. Impairment was defined as scoring below the 16th percentile on a validated cognitive assessment scale. Prior MI, stroke, and CABG were established using hospital surveillance, history, and record review. After adjustment for age, years of education, and years of childhood spent in Japan, men with prior stroke were significantly more likely than others to have poor cognitive performance (odds ratio 4.4, 95% confidence limits 3.0 to 6.7). History of > 1 stroke was associated with an odds ratio of 50 (95% confidence limits 10.5 to 238.3). There was no significant association between cognitive performance and > or = 1 prior MI or history of CABG. Time between events and cognitive function testing did not affect results. Analyses support a significant association between clinical stroke and persistent cognitive impairment, but fail to implicate CABG or MI.

Prolonged QTc interval, impaired pulmonary function, and a very lean body mass jointly predict all-cause mortality in elderly men.

PURPOSE: Assess the joint impact of prolonged QTc interval (QT interval corrected for heart rate), impaired lung function, and low body weight on all-cause mortality. METHODS: This is a population-based, prospective study of the Honolulu Heart Program cohort, performed in Oahu Island, Hawaii, during the 1991-1993 fourth examination of cohort survivors. The participants were 3056 Japanese-American men, 71 to 93 years of age. The measurement consisted of: 1) instrument calculated, heart rate corrected QT interval; 2) one second forced expiratory volume (FEV1) as a percentage of age- and height-predicted FEV1; and 3) body mass index (BMI, kg/m2). Relations of subsequent 3 1/2 year, on average, mortality rates with high risk states of these variables are determined. High risk states are QTc > 440 msec, percent predicted FEV1 < or = 80%, and BMI < or = 21 kg/m2. RESULTS: Mortality rates synergistically increase among groups with one, two, or three high risk states. Men having all three high risk states are seven times more likely to die in the follow-up period than men with no high risk conditions. Very thin men having one other high risk state, pulmonary impairment or prolonged QTc, are four times more likely to die. Excluding diabetics, active smokers, or men taking drugs affecting QT interval does not alter findings. Excluding prevalent coronary heart disease decreases mortality rates among joint high risk groups. CONCLUSION: Results are consistent with clinical studies identifying an autonomic neuropathy associated with wasting chronic lung disease, prolonged QTc, and mortality. Aging populations in developed nations will increase the prevalence of diseases associated with these conditions in decades to come.

Obesity, alcohol consumption, smoking, and mortality.

PURPOSE: The goals of this study were to assess prospectively the impact of obesity, alcohol use, and smoking on total mortality and to test the etiologic hypothesis that subjects with two or more of these risk factors may experience an elevated risk of overall mortality. METHODS: Information on body mass index (BMI), alcohol intake, cigarette smoking, and other life-style factors was obtained from a cohort of 8006 Japanese-American men living in Hawaii. They were between 45 and 68 years of age at the initial examination (1965-1968). After 22 years of follow-up that included nearly 159,000 person-years of observation, 2667 deaths from all causes were identified. RESULTS: There was a significant quadratic (J-shaped) relation between BMI and overall mortality. A weaker J-shaped pattern in risk was also present for the intake of alcohol. A strong positive association was observed with pack-years of cigarette smoking. A synergistic interaction between BMI and alcohol was statistically significant (P = 0.0017). Specifically, men who had the lowest body mass (BMI < 21.21 kg/m2) and drank moderately to heavily (> or = 25 oz/mo) experienced a 63% excess risk (relative risk, 1.63; 95% confidence interval; 1.33 - 1.99) compared to a reference group composed of men who had intermediate body mass (BMI, 21.21 - 26.30 kg/m2) and drank occasionally to lightly (0.01 - 24.99 oz/mo). The increase in risk due to the interactive effect of low BMI and high alcohol intake was stronger (and statistically significant) than when each of these risk factors was considered separately (excess risk, 28% and 2%, respectively). There was no significant interaction for BMI and cigarette smoking, for alcohol and cigarette smoking, or for the three factors combined. CONCLUSIONS: The most important finding of this study was that, in addition to confirming that cigarette smoking could shorten life, extreme (high or low) BMI values and high alcohol consumption are each potentially harmful to health, but even more so if moderate or heavy drinking is concomitant with low body mass, a possible indicator for low intake of nutrients.

Cross-sectional and longitudinal changes in total and high-density-lipoprotein cholesterol levels over a 20-year period in elderly men: the Honolulu Heart Program.

PURPOSE: The purpose of this report is to describe levels of total cholesterol and high-density-lipoprotein cholesterol (HDL-C) in a group of elderly men and to compare these levels to those that were observed 20 years earlier. METHODS: From 1965-1968, the Honolulu Heart Program began following 8006 men of Japanese ancestry living on the island of Oahu, Hawaii, in a prospective study of coronary heart disease and stroke. This report presents data for 971 men who participated in a separate fasting study of lipids and lipoproteins that first occurred from 1970-1972 and in those who received repeat examinations 10 and 20 years later. Men were aged 71-93 years at the last examination. RESULTS: Over the 20-year period, total cholesterol declined by 1.6-1.8 mg/dL per year (P < 0.001), from average baseline values of 219-222 mg/dL. Levels of HDL-C rose 0.2-0.3 mg/dL per year (P < 0.001), from average baseline values of 44-46 mg/dL. After adjustment for baseline cholesterol levels, men with prevalent coronary heart disease at the end of the 20-year follow-up experienced significantly greater reductions in total cholesterol levels than men without disease (P < 0.001). Men who developed coronary heart disease within the first 10 years of follow-up had the greatest yearly decline in total cholesterol (1.9 mg/dL), followed by men who developed heart disease later (1.8 mg/dL) and men who remained disease free (1.5 mg/dL). Differences between men with recent and earlier disease were not statistically significant, although men without coronary disease experienced a significantly smaller decrease in total cholesterol than either of these groups (P < 0.05). CONCLUSIONS: Changes in total cholesterol and HDL-C levels with advancing age may be part of a natural aging process. Some changes, however, such as large reductions in total cholesterol, may signal occult disease or declines in overall health. Selective survival may contribute to these findings since improvements in lipid and lipoprotein levels that are beneficial in younger ages were common in this long-lived cohort of men.

Incidence and predictors of diabetes in Japanese-American men. The Honolulu Heart Program.

Reports on the incidence and predictors of diabetes in minority populations are infrequent. The 6-year cumulative incidence of diabetes between 1965 and 1974 was estimated among 7210 Japanese-American men aged 45 to 68 years who were enrolled in the Honolulu Heart Program and were free of clinically recognized diabetes at baseline. The incidence of "possible" diabetes (based on history, medication, or hospital diagnosis) was 12.8% and the incidence of "probable" diabetes (based on diabetic medication) was 5.7%. Estimates of incidence in subjects with a nonfasting glucose concentration less than 225 mg/dL 1 hour after a 50-g load were 9.7 and 4.0%, respectively. Multivariate adjusted odds ratios (ORs) for probable diabetes in all subjects comparing the upper quintile with the lower four quintiles combined for continuous variables indicated statistically significant direct associations with body mass index (OR, 1.69; 95% confidence interval (CI), 1.31 to 2.18), 1-hour postchallenge glucose level (OR, 5.79; 95% CI, 4.58 to 7.33), triglyceride levels (OR, 1.47; 95% CI, 1.14 to 1.91), systolic blood pressure (OR, 1.36; 95% CI, 1.05 to 1.76), and parental history of diabetes (OR, 1.73; 95% CI, 1.29 to 2.33), and an inverse association with physical activity (OR, 0.49; 95% CI, 0.34 to 0.72), using logistic regression models including these variables as well as age, subscapular/triceps skinfold ratio, and hematocrit simultaneously. Associations were similar but slightly weaker in men with glucose levels less than 225 mg/dL and in those who remained free of cardiovascular disease. When older men (55 to 68 years old) were compared with younger (45 to 54 years old) men, associations among the older group were stronger for body mass index, physical activity, and systolic blood pressure and they were weaker for glucose levels, triglyceride values, and parental diabetes. Results suggest that body mass index, physical inactivity, glucose level, and parental diabetes appear to be independent risk factors for diabetes, while triglyceride and systolic blood pressure levels may be markers for an adverse cardiovascular risk factor profile associated with diabetes and may reflect an insulin resistance syndrome.

Characteristics associated with rapid decline in forced expiratory volume.

Cigarette smoking is known to accelerate decline of pulmonary function; however, the role of other factors is less clear. Characteristics of individuals who experienced rapid decline in forced expiratory volume in 1-sec (FEV1) were examined in 4451 Japanese-American men from the Honolulu Heart Program who were aged 45 to 68 years at baseline (1965-1968) and who produced three acceptable FEV1 measures over a 6-year period. Average annual rates of FEV1 decline were calculated by use of within-person regression and were categorized as rapid (> or = 60 ml/y), moderate (30 to 59 ml/y) or slow (< 30 ml/y). Lifestyle and biologic factors were compared by FEV1 decline categories after adjustment for age. A logistic regression model showed that continued smoking during follow-up, cigarette pack-years, wheezing, coronary heart disease, alcohol intake, and reduced subscapular skinfold were significantly associated with rapid FEV1 decline, after adjustment for age, height, cholesterol, an indicator of Japanese diet, and education. When analyses were restricted to continuous smokers, cigarette pack-years, wheezing, and reduced subscapular skinfold were found to be independent predictors. Among never smokers, lower educational attainment was a predictor of rapid FEV1 decline, and the association involving subscapular skinfold approached significance (P < 0.07). These characteristics may be useful in identifying subgroups of the population who are at increased risk of accelerated decline in pulmonary function and thus would be most likely to benefit from appropriate intervention.

Association of insulin levels with lipids and lipoproteins in elderly Japanese-American men.

PURPOSE: Elevated insulin levels have been associated with cardiovascular disease, but the relationship of insulin with other risk factors and its position in the atherosclerotic pathway is uncertain. A cross-sectional study was conducted to determine whether insulin concentrations were associated with lipids and lipoproteins independently of adiposity and other cardiovascular risk factors. METHODS: Subjects included 3417 Japanese-American men from the Honolulu Heart Program who completed a follow-up examination between 1991 and 1993 and were 71-93 years of age. Men were categorized by quintiles of fasting and 2-hour insulin concentration. RESULTS: Age-adjusted mean high-density lipoprotein (HDL) cholesterol and triglyceride levels varied significantly across quintiles of fasting and 2-hour insulin (P < 0.001, tests for trend), but insulin was not related to total cholesterol and low-density lipoprotein (LDL) cholesterol. HDL cholesterol decreased from 59.3 to 43.7 mg/dL and triglycerides increased from 95.6 to 175.8 mg/dL comparing lowest to highest quintiles of fasting insulin, respectively. These associations were slightly stronger in lean than obese subjects and in nondiabetic versus diabetic individuals particularly for 2-hour insulin levels. Multiple linear regression analysis adjusting for several adiposity measures separately (body mass index (BMI), subscapular skinfold thickness, waist circumference, and waist/hip ratio) and other cardiovascular risk factors attenuated associations slightly but they still remained statistically significant. Estimated differences in HDL cholesterol across extreme quintiles of fasting insulin were reduced slightly from 15.6 mg/dL with adjustment for age to 12.5 mg/dL with adjustment for age and BMI, and to 11.3 mg/dL with adjustment for age, BMI, and cardiovascular risk factors. CONCLUSIONS: Insulin concentration was strongly and independently associated with HDL cholesterol and triglycerides in this cohort of elderly Japanese-American men. Since this study was cross-sectional, further investigation is required to determine whether elevated insulin levels are causally related to dyslipidemia.