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Biomedical subjects

Robert D Abbott

Publications and source records attributed to Robert D Abbott.

At least 37 records · Page 2Linked to original sources

High density lipoprotein cholesterol and the risk of stroke in elderly men: the Honolulu heart program.

High density lipoprotein (HDL) cholesterol has been inversely associated with coronary heart disease. Associations with stroke are less clear, particularly among the elderly. In this study, the authors examined the relation between HDL cholesterol levels and the risk of stroke in elderly men. Levels of HDL cholesterol were measured in 2,444 Honolulu Heart Program men aged 71-93 years at the 1991-1993 examinations. The participants, who were free of prevalent stroke, coronary heart disease, and cancer at baseline, were followed to the end of 1998 for thromboembolic and hemorrhagic stroke. While HDL cholesterol was unrelated to hemorrhagic events, incidence of thromboembolic stroke declined consistently with increasing HDL cholesterol level (p = 0.003). There was a nearly threefold excess of thromboembolic stroke in men with low HDL cholesterol levels (<1.0 mmol/liter (<40 mg/dl)) compared with men with high levels (> or =1.6 mmol/liter (> or =60 mg/dl)) (10.6/1,000 person-years vs. 3.6/1,000 person-years; p = 0.001). Adjustment for other risk factors had little effect on these findings, although associations appeared strongest in elderly men with "desirable" total cholesterol levels, hypertension, or diabetes mellitus. These findings suggest that HDL cholesterol level is inversely related to the risk of thromboembolic stroke in elderly men. Whether HDL cholesterol alters the effect of other factors on stroke risk in elderly men warrants further study.

Aged↗

Parkinsonian signs and substantia nigra neuron density in decendents elders without PD.

Substantia nigra (SN) neurons were counted on single, transverse caudal midbrain sections from 217 male participants in the Honolulu-Asia Aging Study, aged 74-97 years at death. Quadrants areas within the SN were determined with a planimeter and neuronal density was expressed as neurons/mm(2) for 10 Parkinson's disease (PD) cases, 29 incidental Lewy body cases, and 178 controls with neither condition. Mean densities in all quadrants were significantly lower in the PD group compared with the other groups (p = 0.006). This relationship was strongest in the ventrolateral quadrant. In a subgroup of 50 controls who were examined with the Unified Parkinson's Disease Rating Scale an average of 2.1 years prior to death, there was an association of stooped posture (p = 0.009), postural instability (p = 0.013), body bradykinesia (p = 0.048), and gait disturbance (p = 0.05) with neuron density in the dorsolateral quadrant; and impaired speech (p = 0.014), abnormal facial expression (p = 0.022), and difficulty rising from a chair (p = 0.032) with neuron density in the dorsomedial quadrant. There was a significant association of increasing number of signs present with decreasing neuron density in both quadrants (p = 0.001 for trend). Low SN neuron density may be the basis for parkinsonian signs in the elderly without PD.

Age Factors↗

Prospective association between low and high total and low-density lipoprotein cholesterol and coronary heart disease in elderly men.

OBJECTIVES: To examine the relationship between total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) and the incidence of coronary heart disease (CHD) in elderly men. DESIGN: Prospective. SETTING: Population based. PARTICIPANTS: A sample of 2,424, Japanese-American men aged 71 to 93 was used. MEASUREMENTS: Six years of data on incident fatal plus nonfatal CHD were examined. RESULTS: Analysis revealed a significant U-shaped relationship between age-adjusted CHD rates and both TC and LDL-C. The ranges of TC and LDL-C with the lowest risk of CHD were 200 to 219 mg/dL and 120 to 139 mg/dL, respectively. As cholesterol concentrations declined and increased beyond these ranges, the risk of CHD increased. These U-shaped relationships remained significant after adjusting for age and other risk factors. CONCLUSION: The U-shaped associations between TC and LDL-C and CHD imply a complex relationship between lipids and CHD in late life. The results indicate that elevated lipid levels should continue to be treated in healthy elderly individuals, as they are in those who are younger, although pharmacologically lowering lipids to excessively low levels in the elderly may warrant further study, as does the contribution of subclinical frailty to the relationship of lipids to CHD risk.

Aged↗

Respiratory symptoms and undiagnosed airflow obstruction in middle-aged adults: the Korean Health and Genome Study.

BACKGROUND: The prevalence of undiagnosed airflow obstruction is difficult to measure since it requires screening in population-based samples to identify individuals free of clinical symptoms. The purpose of this report is to examine the prevalence of undiagnosed airflow obstruction and its relation with respiratory symptoms in middle-age adults in the Korean Health and Genome (KHG) Study. METHODS: The KHG study is an ongoing population-based study of Korean adults aged 40 to 69 years. The current report includes 8,140 men and women without a pulmonary disorder or obstructive lung disease. In this sample, undiagnosed airflow obstruction was defined on the basis of spirometric testing and in the absence of a medical history or a recognized pulmonary disorder. Respiratory symptoms included chronic cough, chronic phlegm, wheezing, and shortness of breath. RESULTS: Undiagnosed airflow obstruction was observed in 12.4% of the men (470 of 3,806 subjects) and in 3.5% of the women (152 of 4,334 subjects). In men, the age-adjusted prevalence of undiagnosed airflow obstruction increased consistently with increasing number of respiratory symptoms. In those who smoked, there was a 2.3-fold excess in its prevalence when three or more symptoms were present, as compared to when they were absent (27.4% vs 12.0%, p < 0.001). A 2.4-fold excess (20.6% vs 8.5%, p = 0.004) was observed in nonsmoking men, in whom respiratory symptoms were consistently less common than in those who smoked. Respiratory symptoms were unrelated to undiagnosed airflow obstruction in women smokers, although only 3.9% smoked cigarettes. In women who were nonsmokers, the prevalence of undiagnosed airflow obstruction increased from 2.3% in those without a respiratory symptom to 6.0% when three or more symptoms were present (p = 0.003). CONCLUSIONS: Findings suggest that undiagnosed airflow obstruction is common in Korea with several respiratory symptoms. Whether respiratory symptoms with associations with undiagnosed airflow obstruction can be used to design early intervention strategies that prevent or delay the onset of COPD and its disabling consequences warrants further study.

Adult↗

Adolescent heavy episodic drinking trajectories and health in young adulthood.

OBJECTIVE: This study examined the association of trajectories of heavy episodic drinking (at least five alcoholic drinks on one occasion) during adolescence with health status and practices at age 24. METHOD: Semiparametric group-based modeling and logistic regressions were used to analyze data from a longitudinal panel of 808 youths interviewed between 10 and 24 years of age. RESULTS: Four distinct trajectories of adolescent heavy episodic drinking were identified: nonheavy drinkers, late onsetters, escalators and chronic heavy drinkers. Overall, young adults who did not engage in heavy episodic drinking during adolescence had the lowest occurrence of health problems and were most likely to engage in safe health behaviors at age 24. Chronic and late-onset heavy episodic drinking during adolescence had negative effects on health status and practices at age 24. Adolescent chronic heavy drinkers were more likely to be overweight or obese and to have high blood pressure at age 24 than those who did not drink heavily in adolescence. Late-onset heavy drinkers were less likely to engage in safe driving practices at age 24 and were more likely to have been ill in the past year than adolescents who did not drink heavily. These health disparities remained even after current frequency of heavy episodic drinking at age 24, other adolescent drug use, ethnicity, gender and family poverty were controlled. CONCLUSIONS: Heavy episodic alcohol use during adolescence has long-term, negative health consequences. Distinct patterns of adolescent heavy drinking affect health status and practices in young adulthood differently.

Adolescent↗

C-reactive protein, cardiovascular disease and stroke: new roles for an old biomarker.

Stroke is a leading cause of death and disability worldwide. A new and exciting development in cardiovascular disease is the recognition of the role of inflammation in atherosclerosis. C-reactive protein, an acute phase reactant, appears to be a promising biomarker for cardiovascular disease, possibly more predictive than cholesterol and also may play an etiological role. C-reactive protein also appears to be predictive of stroke risk, although less so in the elderly. Although the number of studies on stroke (apart from cardiovascular disease) is limited, there is a significant graded increase in stroke risk within the low-to-high normal range of C-reactive protein. C-reactive protein is readily amenable to treatment with anti-inflammatory drugs, such as aspirin and statins. New and increasingly available high-sensitivity assays may make C-reactive protein a standard screening tool for cardiovascular disease.

Biomarkers↗

Pathways from physical childhood abuse to partner violence in young adulthood.

Analyses investigated several competing hypotheses about developmental pathways from childhood physical abuse and early aggression to intimate partner violence (IPV) for young adult males and females at age 24. Potential intervening variables included: adolescent violence (age 15 to 18), negative emotionality at age 21, and quality of one's relationship with an intimate partner at age 24. At the bivariate level, nearly all variables were associated in the expected directions. However, tests of possible intervening variables revealed only a few significant results. For males, a strong direct effect of abuse on later partner violence was maintained in each model. For females, the quality of one's relationship with an intimate partner did appear to mediate the effect of childhood abuse on later violence to a partner, raising the possibility of gender differences in developmental pathways linking abuse to IPV. Implications with regard to prevention are discussed.

Adolescent↗

Dietary magnesium intake and the future risk of coronary heart disease (the Honolulu Heart Program).

Magnesium (Mg) deficiency is believed to have adverse cardiovascular consequences that are broad and complex, although an association between dietary Mg intake and the risk of coronary heart disease (CHD) has not been clearly identified. The purpose of this study is to examine the relation between dietary Mg intake and future risk of CHD. Reported findings are based on dietary Mg intake in 7,172 men in the Honolulu Heart Program. Intake of Mg was recorded at baseline examinations that took place from 1965 to 1968 when the men were aged 45 to 68 years. In 30 years of follow-up, 1,431 incident cases of CHD were identified. Within 15 years after dietary assessment, the age-adjusted incidence decreased significantly from 7.3 to 4.0 per 1,000 person-years in the lowest (50.3 to 186 mg/day) versus highest (340 to 1,183 mg/day) quintiles of Mg intake (p <0.001). When adjustments were made for age and other nutrients (singly or combined), there was a 1.7- to 2.1-fold excess in the risk of CHD in the lowest versus highest quintiles (p <0.001). The excess risk ranged from 1.5- to 1.8-fold after further adjustment for other cardiovascular risk factors (p <0.05). Associations between dietary Mg and coronary events occurring after 15 years of follow-up were modest. We conclude that the intake of dietary Mg is associated with a reduced risk of CHD. Whether increases in dietary Mg intake can alter the future risk of disease warrants further study.

Aged↗

C-reactive protein and the future risk of thromboembolic stroke in healthy men.

BACKGROUND: Evidence suggests that C-reactive protein (CRP) is related to thromboembolic (TE) stroke. Whether associations are altered in the presence of other risk factors is unclear. The purpose of this study was to additionally assess the relation between CRP and TE stroke. METHODS AND RESULTS: On the basis of 20 years of follow-up after CRP measurement, 259 cases of TE stroke were identified and compared with 1348 controls. Subjects were aged 48 to 70 years when CRP was measured. Levels of CRP were positively associated with TE stroke throughout the 20 years of follow-up. Although associations were modest within 5 years of CRP measurement, the odds of stroke in the top versus bottom CRP quartile increased over time to a 3.8-fold excess by 10 to 15 years into follow-up (P<0.001). For men without hypertension or diabetes, the overall corresponding odds were 1.6 to 1.7 (P<0.05). In men 55 years of age, and in those with hypertension or diabetes were not significant. CONCLUSIONS: Findings suggest that elevated CRP in middle adulthood and in men with healthier risk factor profiles may be important as a risk factor for TE stroke. Use of CRP levels as a clinical screen to identify an increased risk of cardiovascular disease in otherwise healthy men warrants consideration.

Aged↗

Environmental, life-style, and physical precursors of clinical Parkinson's disease: recent findings from the Honolulu-Asia Aging Study.

BACKGROUND: Increased westernization with Japanese migration to the U. S. in the early 20(th) century is thought to have altered the risk of cardiovascular disease. Whether similar effects include changes in the risk of Parkinson's disease (PD) is not clear. This report describes the relations between environmental, life-style, and physical attributes and the incidence of PD that have been observed in the Honolulu-Asia Aging Study. METHODS: Beginning in 1965, environmental, life-style, and physical attributes were recorded at selected examinations in a cohort of 8,006 Japanese-American men. Subjects were followed for clinical PD. FINDINGS: During 30 years of follow- up, PD was observed in 137 men. Overall incidence (7.1/10,000 person-years) was generally higher than in Asia and similar to rates observed in Europe and the U. S. Precursors of PD included constipation, adiposity, years worked on a sugar or pineapple plantation, years of exposure to pesticides, and exposure to sugar cane processing. Factors showing an inverse association with PD included coffee intake and cigarette smoking. Among dietary factors, carbohydrates increased the risk of PD while the intake of polyunsaturated fats appeared protective. Total caloric intake, saturated and monounsaturated fats, protein, niacin, riboflavin, beta-carotene, vitamins A, B, and C, dietary cholesterol, cobalamin, alpha-tocopherol, and pantothenic acid showed no clear relation with clinical PD. INTERPRETATION: Findings suggest that several environmental, life-style, and physical attributes appear to be precursors of PD. Whether patterns of precursors can be used to identify individuals at high risk of future PD or can broaden the scope of early interventions or recruitment into neuroprotective trials warrants further study.

Aged↗

Age-related changes in risk factor effects on the incidence of thromboembolic and hemorrhagic stroke.

We examined the changes in risk factor effects on the incidence of thromboembolic and hemorrhagic stroke as they may occur with age. Findings were based on repeated risk factor measurements at four examinations over a 26-year period in 7589 men in the Honolulu Heart Program. After each examination, 6 years of follow-up were available to assess risk factor effects on the incidence of stroke over a broad range of ages (45-93 years). As compared with normotensive men, the risk of thromboembolic stroke in the presence of hypertension declined from a 7-fold excess in men aged 45 to 54 years to a 1.4-fold excess in men aged > or =75 (P<.001). Adverse effects of diabetes and atrial fibrillation seemed to be equally important across all ages, whereas a protective effect of physical activity increased with age. Except for men with atrial fibrillation, the incidence of thromboembolic stroke increased significantly with age regardless of risk factor status, including men with normal blood pressure (P<.001). Although hemorrhagic events were less common, positive relations with cigarette smoking seemed to strengthen with age, whereas those with hypertension tended to decline. Our findings suggest that strategies for the prevention of stroke may need to account for changes in risk factor effects as they occur with age. Control of diabetes and the encouragement of active lifestyles in the elderly seem to be especially important.

Aged↗

Plantation work and risk of Parkinson disease in a population-based longitudinal study.

CONTEXT: Parkinson disease (PD) has an unknown cause; however, convincing evidence is emerging that indicates pesticides can selectively injure the dopaminergic system in laboratory animals. Retrospective studies in humans demonstrate a link between exposure to agricultural lifestyle factors and PD. OBJECTIVE: To determine whether working on a plantation in Hawaii and exposure to pesticides are associated with an increased risk of PD decades later. DESIGN AND SETTING: Prospective cohort study based on the island of Oahu, Hawaii, with 30 years of follow-up. Years of work on a plantation were assessed by questionnaire at study enrollment in 1965. Self-reported information on pesticide exposure was collected at a separate examination 6 years later. PARTICIPANTS: Participants were 7986 Japanese American men born between 1900 and 1919 who were enrolled in the longitudinal Honolulu Heart Program. MAIN OUTCOME MEASURES: Incident PD was determined by medical record review or by an examination conducted by a study neurologist at a later date. RESULTS: During follow-up, 116 men developed PD. Age-adjusted incidence increased significantly among men who worked more than 10 years on a plantation. The relative risk of PD was 1.0 (95% confidence interval, 0.6-1.6), 1.7 (95% confidence interval, 0.8-3.7), and 1.9 (95% confidence interval, 1.0-3.5) for men who worked on a plantation 1 to 10 years, 11 to 20 years, and more than 20 years compared with men who never did plantation work (P =.006, test for trend). Age-adjusted incidence of PD was higher in men exposed to pesticides than in men not exposed to pesticides although this was not statistically significant (P =.10, test for trend). CONCLUSION: These longitudinal observations regarding plantation work in Hawaii support case-control studies suggesting that exposure to pesticides increases the risk of PD.

Aged↗

Effects of the Seattle social development project on sexual behavior, pregnancy, birth, and sexually transmitted disease outcomes by age 21 years.

OBJECTIVE: To examine the long-term effects of the full Seattle Social Development Project intervention on sexual behavior and associated outcomes assessed at age 21 years. DESIGN: Nonrandomized controlled trial with long-term follow-up. SETTING: Public elementary schools serving children from high-crime areas in Seattle, Wash. PARTICIPANTS: Ninety-three percent of the fifth-grade students enrolled in either the full-intervention or control group were successfully interviewed at age 21 years (n = 144 [full intervention] and n = 205 [control]). INTERVENTIONS: In-service teacher training, parenting classes, and social competence training for children. MAIN OUTCOME MEASURES: Self-report measures of all outcomes. RESULTS: The full-intervention group reported significantly fewer sexual partners and experienced a marginally reduced risk for initiating intercourse by age 21 years as compared with the control group. Among females, treatment group status was associated with a significantly reduced likelihood of both becoming pregnant and experiencing a birth by age 21 years. Among single individuals, a significantly increased probability of condom use during last intercourse was predicted by full-intervention group membership; a significant ethnic group x intervention group interaction indicated that after controlling for socioeconomic status, single African Americans were especially responsive to the intervention in terms of this outcome. Finally, a significant treatment x ethnic group interaction indicated that among African Americans, being in the full-intervention group predicted a reduced probability of contracting a sexually transmitted disease by age 21 years. CONCLUSION: A theory-based social development program that promotes academic success, social competence, and bonding to school during the elementary grades can prevent risky sexual practices and adverse health consequences in early adulthood.

Adolescent↗

C-reactive protein and myocardial infarction.

C-reactive protein (CRP) has been shown to predict cardiovascular disease. Whether predictions differ across risk factor strata and for short and long-term follow-up has not been clearly examined. The purpose of this report is to assess the relation between CRP and the development of myocardial infarction (MI) over a 20-year period in men in the Honolulu Heart Program. Subjects were aged 48 to 70 years and free of prevalent disease at the time when CRP levels were measured and follow-up began. Using a case-control design, 369 cases of MI were compared with 1,348 control subjects. After risk factor adjustment, the odds of an MI rose with increasing levels of CRP as early as 5 years into follow-up (P = 0.009). Associations appeared to persist beyond this time, but after 15 years, effects became modest. Adverse effects of an elevated CRP level were observed in middle-aged men (< or =55 years), in men without hypertension or diabetes, and in those who were nonsmokers (P < 0.05). Although positive effects were also observed in those who were hypertensive and smoking at the time of CRP measurement, findings suggest that in clinically healthy men, atherosclerosis could have origins more closely linked with inflammation than with other processes.

Adult↗

Age-related changes in risk factor effects on the incidence of coronary heart disease.

PURPOSE: The purpose of this report is to examine the potential for risk factor effects on the incidence of CHD to change over a broad range of ages from middle adulthood to late-life. METHODS: Findings are based on repeated risk factor measurements at four examinations over a 26-year period in men enrolled in the Honolulu Heart Program. After each examination, six years of follow-up were available to assess risk factor effects as the cohort aged from 45 to 93 years. RESULTS: Based on 18,456 person intervals of follow-up, 677 men developed CHD (3.7%). After risk factor adjustment, a positive relation between hypertension and CHD declined significantly with age (p = 0.013), primarily due to a large increase in the risk of CHD in elderly men (75 to 93) without hypertension. Effects of total cholesterol on CHD also seemed to decline with advancing age, although changes were not statistically significant. In contrast, men with diabetes had a consistent 2-fold excess risk of CHD across all age groups, while a positive association with body mass index in younger men (45 to 54) became negative in those who were the oldest (75 to 93). Due to infrequent smoking in the elderly, associations between smoking and CHD weakened with age. In the oldest men (75 to 93), alcohol intake was unrelated to CHD, while effects of sedentary life-styles on promoting CHD appeared stronger than in those who were younger. CONCLUSION: Findings suggest that changes in risk factor effects on the incidence of CHD with advancing age may require updated strategies for CHD prevention as aging occurs.

Age Factors↗

Developmental relationships between adolescent substance use and risky sexual behavior in young adulthood.

PURPOSE: To examine the developmental relationship between adolescent substance use and risky sexual behavior in young adulthood. A gender-balanced, ethnically diverse urban sample of 808 children in Seattle was surveyed at age 10 years in 1985 and followed prospectively to age 21 years in 1996. Semiparametric group-based modeling was used to determine trajectory groups of binge-drinking, cigarette smoking, marijuana use, and the use of other illicit drugs. Negative binomial regressions and logistic regressions were used to examine whether these trajectory groups predicted the number of sex partners and condom use at age 21 years. Specific forms of adolescent substance use significantly predicted risky sexual behavior at age 21 years, after other substance use and early measures of sexual behavior were controlled. Early binge-drinkers had significantly more sex partners than nonbinge-drinkers. Late onset binge-drinkers and marijuana users had significantly more sex partners and were less likely to use condoms consistently than those who did not binge drink or use marijuana. Experimenters in cigarette smoking, who did not escalate smoking, were more likely to use condoms consistently than nonsmokers. In contrast, the use of other illicit drugs in adolescence did not predict risky sexual behavior at age 21 years. The effects of adolescent substance use on risky sexual behavior at age 21 years differed for youths with developmentally different substance use trajectories in this urban sample disproportionately drawn from high crime neighborhoods. To prevent risky sexual behavior among young adults, attention should be paid to binge-drinking and marijuana use during adolescence.

Adolescent↗

A developmental analysis of sociodemographic, family, and peer effects on adolescent illicit drug initiation.

OBJECTIVE: To examine the effects of sociodemographic, family, and peer predictors on the developmental patterns of illicit drug initiation from ages 12 to 21 years. METHOD: A gender-balanced, ethnically diverse urban sample of 808 children in Seattle was surveyed at age 10 in 1985 and followed prospectively to age 21 in 1996. Discrete-time survival analysis was used to assess the effects of sociodemographic, family, and peer factors on the risk of initiation. RESULTS: The risk for initiating illicit drug use increased steadily from ages 12 to 21. High family conflict, low family bonding, and high peers' antisocial activities predicted higher risk of initiation across this developmental period. The effect of family bonding began to decline after age 18, while the effect of peers' antisocial activities began to increase after age 15. Few gender and ethnic differences were found. CONCLUSIONS: Prevention programs need to include family and peer factors as important targets. Parents should create a warm and supportive family environment with appropriate supervision and control throughout adolescence. Association with antisocial peers should be reduced, especially in high school. Interventions addressing these family and peer factors should have beneficial effects across gender and ethnic groups.

Adolescent↗

A randomized, double-blind, placebo-controlled trial of porcine versus synthetic secretin for reducing symptoms of autism.

OBJECTIVE: To compare the effects of a single dose of biologic and synthetic porcine secretin to placebo on a variety of autism symptoms. METHOD: Eighty-five children with autism without other medical conditions and not taking other psychotropic medications participated (ages between 3 and 12 years, mean IQ = 55). Children were grouped into trios matched by age and communication level and then randomly assigned to one of three treatment groups: biologic secretin (2 CU/kg), synthetic secretin (0.4 microg/kg), and placebo. Measures collected 1 week before and 4 weeks after infusion included autism symptoms, language skills, and problem behaviors, gathered from parents, teachers, and investigators, who were all blind to treatment. Two-factor, repeated-measures analyses of variance (3 treatment levels by 2 repeated measures, pre- and postinfusion) were used to examine efficacy. RESULTS: Direct observation measures did not show change over time related to secretin. Parent reports showed an overall reduction of symptom severity for all treatment groups, including the placebo group. One teacher-report measure showed decreases in autism symptoms in the placebo and synthetic secretin groups. CONCLUSIONS: No evidence that either biologic or synthetic secretin provided amelioration of symptoms beyond placebo was observed. This held true when children with and without gastrointestinal problems were examined separately.

Autistic Disorder↗