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Biomedical subjects

C G Hames

Publications and source records attributed to C G Hames.

At least 37 records · Page 2Linked to original sources
PubMed1985

The relationship of weight change to changes in blood pressure, serum uric acid, cholesterol and glucose in the treatment of hypertension.

In the Hypertension Detection and Follow-up Program (HDFP), elevated blood pressure (BP) was treated by rigorous, stepped care (SC) therapy among half the participants, while the other half were referred to usual sources of care (referred care, RC). There was no program to reduce weight, however, some participants changed weight voluntarily over the first 2 yr, providing an opportunity to examine the role of weight change in the development of diuretic-induced hyperuricemia, hyperglycemia and hypercholesterolemia. There was a stepwise progression from decreased glucose, uric acid and cholesterol concentrations, and BP associated with maximum weight loss to increased values with maximum weight gain. In SC, systolic BP declined by 22.4% among weight-losers and by 17.1% among weight-gainers; in RC, it was 14.4 and 8.1%, respectively. The pattern in diastolic blood pressure and weight change was similar but not as marked. These findings suggest the potential importance of weight loss in enhancing effectiveness of antihypertensive drug treatment and attenuating increases in glucose, uric acid, and cholesterol associated with diuretic treatment of hypertension. The weight change analyses are based on postrandomization observations and do not reflect experimental changes.

Blood Glucose↗
PubMed1985

The black/white mortality crossover: investigation in a community-based study.

The black/white mortality crossover at about age 75, a result of lower white mortality rates at younger ages and lower black rates at the oldest ages, has been observed in U.S. vital statistics since 1900. Though a persistant observation in such data, its validity has been challenged by questions about census enumeration and age reporting on death certificates. Analyses of 20 years experience of all-cause mortality in the community-based Evans County Study using a Weibull model of age specific mortality rates showed a statistically significant black/white mortality crossover for both men (at age 73) and women (at age 85). The finding of a crossover in this longitudinally followed population is significant because the age reporting for both survivors and age at death for nonsurvivors were obtained in the study protocol and did not rely on age reporting either in census data or on the death certificate. Differences in the age and sex patterns of mortality between two populations living in the same geographic region are relevant to questions about the etiology of the major age-related chronic diseases as well as to topics of current interest in health care policy.

Adult↗
PubMed1985

Menopausal change in serum cholesterol. Black/white differences in Evans County, Georgia.

The relationship between menopausal status and total serum cholesterol was examined cross-sectionally in a population of 40- to 54-year-old black and white women of Evans County, Georgia. The relationship differed in blacks and whites as assessed by a significant interaction term in linear regression. Controlling for age, Quetelet index, and smoking status, white postmenopausal women showed an estimated increase in total serum cholesterol of 25 mg/dl (p less than 0.001) compared with premenopausal whites, whereas black postmenopausal women showed no significant increase in total serum cholesterol compared with premenopausal blacks. The authors were unable to attribute the lack of menopausal effect in blacks to selection or measurement bias, nor did confounding or effect modification by obesity or social status negate their findings. Of six other populations in which menopausal influence on total serum cholesterol has been examined, only Pima Indians failed to show a significant increase.

Adult↗
PubMed1984

Relation of serum vitamins A and E and carotenoids to the risk of cancer.

Epidemiologic studies suggest that low carotene intake and low levels of serum retinol may be associated with an increased risk of cancer. Likewise, in some animal studies vitamin E has been associated with a reduced rate of induced cancers. Therefore, we measured retinol, retinol-binding protein, vitamin E (alpha-tocopherol), and total carotenoids in serum collected in 1973 from 111 participants in the Hypertension Detection and Follow-up Program who were free of cancer at the time but were diagnosed as having cancer during the subsequent five years. These measurements were compared with those in 210 controls who were matched for age, sex, race, and time of blood collection, and who remained free of cancer. Mean values for retinol were similar for cases and controls (67.3 and 68.7 micrograms per deciliter, respectively [95 per cent confidence limits for case-control difference, -6.7 to 3.5]). Values were also similar for retinol-binding protein (6.01 and 5.94 mg per deciliter [-0.42 to 0.56]), and carotenoids (114.5 and 111.6 micrograms per deciliter [-9.1 to 15.9]). The mean base-line retinol level in the 18 subjects with subsequent lung cancer was higher than that in their matched controls (79.0 vs. 71.4 micrograms per deciliter, -4.9 to 19.7). Serum vitamin E levels were somewhat lower in subjects who later had cancer than in controls (1.16 and 1.26 mg per deciliter, -0.22 to 0.02), in part because of the confounding effect of serum cholesterol levels (when adjusted for lipid levels, the case-control difference was -0.05 mg per deciliter; -0.17 to 0.07). These data do not support hypotheses relating intake or serum levels of antioxidant vitamins to a reduced cancer risk.

Adult↗
PubMed1984

Ischemic heart disease risk factors and twenty-year mortality in middle-age Evans County black males.

Ischemic heart disease (IHD) risk factors and 20-year mortality rates were studied in middle-aged Evans County black males. We hypothesized, a priori, that blood pressure, cholesterol, and smoking would be predictive of mortality in black males; that black-white differences in mortality would be due to differences in risk factor levels and not risk functions per se; and that social status would be associated with risk factor levels and would be a predictor of mortality. Multivariate analyses of cumulative risk of dying and time to death suggest that the major IHD risk factors are predictors of all-cause and IHD mortality in black males. Black-white differences in risk functions, specifically for cholesterol, were explained by social status: black males and lower social status white males had similar risk functions, different from those of higher social status white males. Black males and lower social status white males had almost identical survival curves, each less favorable than those of higher social status white males.

Adult↗
PubMed1984

Black-white differences in plasma levels of apolipoproteins: the Evans County Heart Study.

Evans County black males had lower ischemic heart disease (IHD) prevalence, incidence, and mortality than white males. High-density lipoprotein (HDL) cholesterol was lower in IHD cases than in subjects without IHD. HDL cholesterol and apolipoprotein A-I (Apo A-I) were higher and low-density lipoprotein (LDL) cholesterol, very low-density lipoprotein (VLDL) cholesterol, and Apo C-II were lower in black than white males. Of the black-white male HDL cholesterol difference, 22% was statistically explained by Apo A-I. Controlling for Apo C-II reduced the black-white differences in total cholesterol 87%, LDL cholesterol 44%, VLDL cholesterol 83%, and total triglyceride 83%. There were negative associations between Apo A-I and age, Quetelet index, and cigarettes smoked; the association between Apo A-I and alcohol was positive. Only body mass index and race were strong correlates of Apo C-II. The ratios of Apo A-I to Apo A-II and of HDL cholesterol to Apo A-II were higher in black than white males with adjustment for age, body mass, and cigarette and alcohol consumption. Thus black-white differences in total lipids, lipoprotein lipids, and lipoprotein apoproteins were observed, indicating a relatively antiatherogenic profile in black males only partially explained by known correlates.

Adult↗
PubMed1984

Immune diagnosis of a subset of Alzheimer's disease with preliminary implications for immunotherapy.

Based on remarkable similarities between the central nervous system and the immune system [e. g., both systems have memory cells, both appear to have identical receptors for dopamine, acetylcholine, enkephalins, endorphins, sharing of antigenic determinants on one or another CNS cell and one or another type of immunocyte cell, both systems communicate by soluble substances (e.g., neurotransmitters and lymphokines, respectively)], we have postulated that some forms of Alzheimer's disease are due not to CNS cell death but rather to excess suppression of the brain "B-cell equivalent". We found a pyrrolidone analog useful in stimulating lymphocyte B-cell mitogenesis and function in vitro; this agent subsequently proved dramatically effective in several patients with severe T cell dysfunction and severe recurrent viral infection due to excess T cell suppression. Its use (3-6 months) proved remarkedly effective in certain patients with Alzheimer's disease (frontal lobe cerebral atrophy on CAT scan, duration at least 2 years). A subset with certain immunological dysfunction responded dramatically both immunologically and clinically. In responders in in vitro studies, the defect was corrected in vitro in the presence of the pyrrolidone analog but not by various neuroleptics. Patients without the defect or with the defect but no in vitro correction by pyrrolidone analog agent did not respond clinically. A switch from pyrrolidone to placebo resulted in immunologic and clinical relapse in 2-4 months.

Adult↗
PubMed1984

Serum retinol and risk of subsequent cancer: extension of the Evans County, Georgia, study.

A previous report from the Evans County, Ga., cohort correlated low base-line retinol levels in 1960-62 to an increased risk of cancer developing in the following 12-14 years. So that this inverse association could be retested, retinol determinations were performed on sera in 135 incident cancer cases, identified during a vital status follow-up in 1981, and in 237 controls matched by race, sex, age, and date of venipuncture. The serum was drawn during the second cohort examination between 1967 and 1969 and stored at -20 degrees C until analysis by high-pressure liquid chromatography in January 1982. Eligible for the study were patients whose initial cancer diagnosis was established more than 24 months after venipuncture. Base-line retinol levels of subsequent cancer cases and their matched controls were similar in the 4 race-sex groups. The risk of cancer at all sites associated with the lowest retinol quintile was similar to that associated with the highest quintile. In multivariate analysis, with control for age, cholesterol, body mass, smoking status, and social class, no significant relationship of serum retinol and case status was found. In summary, these data fail to confirm the strong dose-response relationship between baseline retinol levels and subsequent cancer reported in the previous study.

Female↗
PubMed1984

Hypertension detection and follow-up program study of serum retinol, retinol-binding protein, total carotenoids, and cancer risk: a summary.

In a recently reported study by us, no significant associations were found between retinol, retinol-binding protein (RBP), and total carotenoid levels in prediagnositic serum and the incidence of cancer at all sites combined. Inasmuch as other investigators, in addition to us, have not been able to confirm the two original reports of an inverse association between serum retinol and overall cancer incidence, the relationship, if it exists at all, is probably complex and limited to certain population subgroups. Such subgroups may be defined by extreme values of serum retinol, certain levels of other nutrients, or specific types of cancer. In the present study an inverse association was observed between serum retinol levels and cancer among subjects with low serum selenium levels and for subjects with gastrointestinal cancer. In addition, the risk of cancer was elevated for those individuals with the combination of low serum retinol and high RBP. However, since significant associations will arise by chance alone when many subgroups are examined, these findings are difficult to interpret. Additional studies will be needed to determine whether they are reproducible or are simply the results of chance.

Carotenoids↗
PubMed1983

Prediagnostic serum selenium and risk of cancer.

Selenium levels in serum samples collected in 1973 from 111 subjects in whom cancer developed during the subsequent 5 years were compared with those in serum samples from 210 cancer-free subjects matched for age, race, sex, and smoking history. The mean selenium level of cases (0.129 +/- SEM 0.002 micrograms/ml) was significantly lower than that of controls (0.136 +/- 0.002 micrograms/ml). The risk of cancer for subjects in the lowest quintile of serum selenium was twice that of subjects in the highest. Multivariate adjustment for geographical area and serum levels of lipids, vitamins A and E, and carotene, did not alter this relation. The association between low selenium level and cancer was strongest for gastrointestinal and prostatic cancers. Serum levels of vitamins A and E compounded the effect of low selenium; relative risks for the lowest tertile of selenium were 2.4 and 3.9 in the lowest tertiles of vitamins E and A, respectively.

Adult↗
PubMed1983

Does blood pressure usually rise with age? . . . Or with stress?

To determine whether blood pressure increases commonly accompany the aging process or reports of psychological distress during adulthood, successive blood pressure readings from eight to 14 annual health examinations of 172 employed men were studied. Longitudinal analysis showed that blood pressures tended to decline on the average over the first four examinations, possibly a familiarization effect. Even during the later period (extending four to ten years), 45 percent had no systematic increase in systolic pressure and 60 percent no systematic increase in diastolic pressure (i.e., averaging 0.5 mm/Hg per year or greater). Older and heavier men had higher mean pressures, as did those men with higher anxiety and hostility scores. The slope of blood pressure increase in the later part of the period of observation was greater for individuals who reported lower amounts of stress. There is need to discover additional correlates of systematic blood pressure increase over time. It appears, however, that about half of adult men do not experience steady blood pressure increases with aging. While anxiety and hostility correlate with concurrent blood pressure levels, neither these variables nor other estimates of stress were positively correlated with increasing blood pressure levels over these years.

Adult↗
PubMed1983

Factors contributing to the variability in serum lipid levels and blood pressure in a large kindred.

A 267-member, five-generation Caucasian kindred, that was originally from Evans County, Georgia, and that had a high incidence of cardiovascular disease, was chosen for a study of factors that may make significant contributions to the observed variability in serum lipid levels and blood pressure. A total of 234 of the 240 living members of the family agreed to participate and were examined in the summer of 1978 either at a clinic in Claxton, Georgia, or in their homes. Total serum cholesterol, triglycerides, high density lipoprotein cholesterol, systolic and diastolic blood pressures, height, weight, and two skinfold thicknesses were transformed to natural logarithms, and then adjusted for significant age effects by polynomial regressions on age, separately for each sex. These adjusted variables were then regressed on behavioral traits such as cigarette smoking using a step-wise, multiple linear regression procedure to determine the best fitting linear models. For males, behavioral traits accounted for 41.39% (R2) of the variance in height, 15.01% in weight, 19.51% in subscapular skinfold, 30.28% in triceps skinfold, 10.19% in triglycerides, 8.25% in total cholesterol, 15.81% in high density lipoprotein cholesterol, 21.32% in systolic blood pressure, and 28.23% in diastolic blood pressure. For females, the behavioral traits accounted for 31.40% of the variance in height, 25.99% in weight, 15.80% in subscapular skinfold, 9.84% in triceps skinfold, 7.20% in triglycerides, 21.08% in total cholesterol, 16.69% in high density lipoprotein cholesterol, 9.91% in systolic blood pressure, and 1.55% in diastolic blood pressure.

Age Factors↗
PubMed1982

Serum retinol and the inverse relationship between serum cholesterol and cancer.

Several human studies have shown an inverse relation between vitamin A intake (and serum concentrations of retinol and carotene) and cancer. Serum cholesterol concentrations have also been reported in inverse relation to cancer. In a study of 3102 people in Evans County, Georgia, who were followed for over 12-14 years to assess the incidence of cancer there was an inverse association between the risk of cancer and both serum retinol and serum cholesterol concentrations. The data also showed an unexpectedly strong correlation between serum retinol and total cholesterol concentrations. The inverse relationship with cancer was stronger with serum retinol than with cholesterol, which suggested that the association with cholesterol might be secondary. This suggestion may also explain the cholesterol-cancer association reported in several other cohort studies. Further studies of the relation between serum concentrations of cholesterol, retinol, and carotene and the incidence of cancer are needed.

Cholesterol↗
PubMed1982

Isolated systolic hypertension in Evans county--I. Prevalence and screening considerations.

Studies suggest that isolated hypertension involves pathophysiological change different from essential hypertension; while clinical trials of drug treatment of isolated systolic hypertension are underway, little is known of its descriptive epidemiology. This paper reports characteristics of isolated systolic hypertension in biracial Evans County, Georgia, 1967-69. Isolated systolic hypertension was rare below age 40, but the percent prevalence increased greatly at older ages. Defining isolated systolic hypertension as diastole blood pressure (DBP) less than 95 and systolic blood pressure (SBP) greater than 160, age-adjusted percent prevalence at ages 40 and above were 9.6, 10.6, 15.1, and 18.3 for white males, black males, white females, and black females respectively. Percent prevalence declined to 4.8, 6.3, 9.7, and 12.7 in the four race/sex groups when a DBP cutoff of 90 was used. Unlike essential hypertension, percent prevalence of isolated systolic hypertension varied more by sex than by race: it was 60-100% higher in females than in males and only 10--30% higher in blacks than in whites. Percent prevalence of isolated systolic hypertension for the second and third of three BP readings (one clinic visit) increased compared to the first reading, the reverse of what is usually found for essential hypertension. DBP variability was relatively greater than SBP variability and probably accounted for the changes in percent prevalence. These data support clinical studies indicating isolated systolic hypertension is a distinct syndrome. This condition, shown to be a risk factor for death and disease in other studies, was common at older ages and may increasingly become health problem as the population ages.

Adult↗
PubMed1982

Autoantibodies and immunoglobulin allotypes in healthy North American Blacks of different age groups.

A population of 291 healthy North American Black subjects of different ages was studied for immunoglobulin (Ig) allotypes and the prevalence of autoantibodies, to determine possible associations between Ig allotypes and age, autoantibodies and age, and Ig allotypes and autoantibodies. Indirect immunofluorescence was used to detect anti-gastric parietal cell, anti-smooth muscle, anti-thyroid microsomal, anti-nuclear, and anti-mitochondrial antibodies. The sera were typed for the Ig allotypes Gm(1, 2, 3, 5, 6, 13, 14, 17, and 21) and Km(1) with a hemagglutination-inhibition assay. A significant association between advanced age and an increased prevalence of anti-nuclear antibodies was observed in females. There was no significant association between Ig allotypes and the autoantibodies tested. The results suggest that Ig allotypes are not involved in the development of autoantibodies in healthy Blacks.

Adolescent↗
PubMed1981

Serum vitamin A (retinol) and cancer incidence in Evans County, Georgia.

A total community sample of 3,102 individuals from Evans County, Georgia, was followed for 12-14 years. During this period, 129 documented new cases of cancer were ascertained from medical records and death certificates. Cases were considered for inclusion only if documented at least 12 months after subjects were inducted into the cohort study. Cases were classified as definite, probable, and possible by strict criteria. Blood samples were drawn at the beginning of the study in 1960-62 and sera were frozen. Serum vitamin A (retinol) levels were measured in 1976 on the stored sera of 85 cancer patients and for 174 age-, race-, and sex-matched controls. Retinol estimations were performed by a fluorometric method after alumina column separation. Experiments conducted to simulate the exposure to light, thawing, and refreezing that sera may have undergone during the 14-16 years of storage showed retinol to be quite stable in response to these possible insults. As compared to controls, persons that eventually developed cancer had significantly lower mean serum retinol levels at least 12 months before the cancer diagnosis. The association was in the same direction for all 4 race-sex groups, although stronger overall for males than females, and was consistent for the various cancer sites and cell types. Both matched and regression residual analyses were used to control for the confounding variables considered: age, race, sex, obesity, social class, and smoking.

Age Factors↗