Biological dosimetry: the potential use of radiation-induced apoptosis in human T-lymphocytes

An assay for biological dosimetry based on the induction of apoptosis in human T-lymphocytes is described. Radiation-induced apoptosis was assessed by flow cytometric identification of cells displaying apoptosis-associated DNA condensation. CD4 and CD8 T-lymphocytes were analysed. They were recognized on the basis of their cell-surface antigens. Four parameters were measured for both cell types: cell size, granularity, antigen immunofluorescence and DNA content. Apoptosis was quantified as the fraction of CD4-, or CD8-positive cells with a characteristic reduction of cell size and DNA content. At doses below 1 Gy, levels of radiation-induced apoptosis increased for up to 5 days after irradiation. Optimal dose discrimination was observed 4 days after irradiation, at which time the dose-response curves were linear, with a slope of 8% +/- 0.5% per 0.1 Gy. In controlled, dose-response experiments the lowest dose level at which the radiation-induced apoptosis frequency was still significantly above control was 0.05 Gy. After 5 days post-irradiation incubation, intra- and interdonor variations were measured and found to be similar; thus, apoptotic levels depend more on the dose than on the donor. The results demonstrate the potential of this assay as a biological dosimeter.

Predictors of progression from impaired glucose tolerance to NIDDM: an analysis of six prospective studies

Risk factors associated with the progression from impaired glucose tolerance (IGT) to NIDDM were examined in data from six prospective studies. IGT and NIDDM were defined in all studies by World Health Organization (WHO) criteria, and baseline risk factors were measured at the time of first recognition of IGT. The studies varied in size from 177 to 693 participants with IGT, and included men and women followed from 2 to 27 years after the recognition of IGT. Across the six studies, the incidence rate of NIDDM was 57.2/1,000 person-years and ranged from 35.8/1,000 to 87.3/1,000 person-years. Although baseline measures of fasting and 2-h postchallenge glucose levels were both positively associated with NIDDM incidence, incidence rates were sharply higher for those in the top quartile of fasting plasma glucose levels, but increased linearly with increasing 2-h postchallenge glucose quartiles. Incidence rates were higher among the Hispanic, Mexican-American, Pima, and Nauruan populations than among Caucasians. The effect of baseline age on NIDDM incidence rates differed among the studies; the rates did not increase or rose only slightly with increasing baseline age in three of the studies and formed an inverted U in three studies. In all studies, estimates of obesity (including BMI, waist-to-hip ratio, and waist circumference) were positively associated with NIDDM incidence. BMI was associated with NIDDM incidence independently of fasting and 2-h post challenge glucose levels in the combined analysis of all six studies and in three cohorts separately, but not in the three studies with the highest NIDDM incidence rates. Sex and family history of diabetes were generally not related to NIDDM progression. This analysis indicates that persons with IGT are at high risk and that further refinement of risk can be made by other simple measurements. The ability to identify persons at high risk of NIDDM should facilitate clinical trials in diabetes prevention.

Metabolic correlates of obesity and radiographic features of knee osteoarthritis: data from the Baltimore Longitudinal Study of Aging

OBJECTIVE

To examine the relationship between metabolic correlates of obesity and radiographic knee osteoarthritis (OA).

METHODS

We included 464 Caucasian men and 275 Caucasian women aged 40 years and above who were participants in the Baltimore Longitudinal Study of Aging. Subjects had bilateral anteroposterior standing knee radiographs read for features of OA using Kellgren-Lawrence scales. Resting blood pressure, fasting lipids, 2 h oral glucose tolerance test, and anthropometric measurements were obtained at the same visit as the knee radiograph. Metabolic correlates of obesity were compared between subjects with Kellgren-Lawrence grade > or = 2 (definite knee OA) and grade 0 (normal radiograph) by sex.

RESULTS

Both men and women with knee OA had higher unadjusted systolic blood pressure than those with normal knee radiographs; unadjusted measures of glucose metabolism and lipids did not vary by presence of knee OA in men or women. After adjustment for age and obesity, systolic blood pressure did not vary by presence of knee OA in men. While women with knee OA did have higher adjusted mean systolic blood pressure than women with normal radiographs (127 +/- 2.4 vs 120 +/- 2.2 mm Hg; p = 0.04), both values were within normal range. Unexpectedly, men with knee OA had lower adjusted mean 2 h glucose levels compared to men without OA (7.5 +/- 0.2 vs 8.4 +/- 0.2 mmol/l; p = 0.01). Other adjusted variables did not differ by presence of knee OA.

CONCLUSION

These data do not support the hypothesis that metabolic correlates of obesity are independently associated with radiographic knee OA after adjustment for age and obesity.

Acetylator phenotype in relation to age and gender in the Baltimore Longitudinal Study of Aging

This study investigated in healthy Caucasians the possible occurrence of age and gender-associated differences in NAT2 acetylator phenotype. Acetylator phenotype was determined after a single oral dose of 100 mg dapsone during testing of oral glucose tolerance in 510 Caucasian volunteers aged from 19 to 93 years, 339 men and 171 women, from the Baltimore Longitudinal Study of Aging. Participants were classified as slow or rapid acetylators according to the ratio of monoacetyldapsone to dapsone concentration in plasma. The ratio dividing the two groups, 0.30, was chosen after inspection of a probit plot and histogram of the monoacetyldapsone/dapsone ratios. Fifty-one percent of the participants were slow acetylators and 49% were rapid acetylators. Because there was no significant difference between the sexes in the monoacetyl-dapsone/dapsone ratios, all 510 participants were pooled into a single group for further analysis. In the combined analysis, there was a small decline in the prevalence of the slow acetylator phenotype with age, but this age effect accounted for less than 1% of the total variance in the monoacetyldapsone/dapsone ratio (r2 = 0.009). Also, it was shown in a group of 20 participants that administration of glucose with dapsone does not influence the determination of acetylator phenotype. In a large healthy Caucasian. American population, there was no biologically important effect of age or sex on the distribution of NAT2 acetylator phenotype.

The effect of age on insulin resistance and secretion: a review

Aging is associated with an increased incidence of hypertension, noninsulin-dependent diabetes mellitus, and coronary heart disease. Because these conditions often cluster in the same individuals, there has been speculation that a common mechanism is responsible for all of these pathological states. Both epidemiological and clinical research has shown that insulin resistance and/or hyperinsulinemia are associated with glucose intolerance, dyslipidemia (high plasma triglyceride and low high-density lipoprotein-cholesterol levels), and higher systolic and diastolic blood pressures. Therefore, insulin resistance and hyperinsulinemia have been proposed as the causal link among the elements of the cluster mentioned above, now most commonly referred to as the insulin resistance syndrome, syndrome X, or the metabolic syndrome. The elderly are more glucose intolerant and insulin-resistant, but it remains controversial whether this decrease in function is an inevitable consequence of "biological aging" or the result of what might be referred to as environmental or lifestyle variables: increased obesity, a detrimental pattern of fat distribution, or physical inactivity that usually accompany age. All of these modifiable environmental factors have also been shown to result in increases in insulin resistance and hyperinsulinemia and are risk factors for the development of the diseases of the metabolic syndrome. Recent interventional studies that have attempted to reverse these conditions in the elderly have shown improved insulin sensitivity, and glucose tolerance. Insulin secretion, on the other hand, seems to decrease with age even after adjustments for differences in adiposity, fat distribution, and physical activity. This may be responsible for the glucose intolerance in the very old even after improvements have been made in their lifestyle variables.

Insulin response during the oral glucose tolerance test: the role of age, sex, body fat and the pattern of fat distribution

To clarify their primary roles on insulin response to oral glucose, age and sex differences in body composition should be taken into account. Oral glucose tolerance tests were performed on 472 men and 299 women of the Baltimore Longitudinal Study of Aging, ranging in age from 20 to 96 years. Subjects who were taking medications or had any diseases which could affect glucose tolerance were excluded. In addition to insulin and glucose values for the glucose tolerance test, we calculated body mass index (BMI), percentage body fat from skinfolds (% Body Fat), waist hip ratio (WHR), mean glucose level over the 2-hour test (GM), the basal insulin (IO), and the mean insulin response over the 2-hour test (IM). There was no significant sex difference in mean age, but men had significantly higher BMI (25.6 vs 24.0 kg/m2), WHR (0.93 vs 0.76), and GM (8.5 vs 7.7 mM), while % Body Fat was lower (25% vs 33%). Unadjusted IO and IM levels were significantly higher in men than in women (51 vs 44 and 303 vs 231 pM--antilogs of log-normalized values). Insulin levels, adjusted for differences in age, % Body Fat, WHR, and GM by analysis of covariance, however, showed no sex differences (49 vs 46 and 282 vs 257 pM). Adjusted insulin levels declined significantly with age; IM fell progressively from 323 pM in 20 to 39-year olds, 267 pM in 40 to 59-year, 253 pM in 60 to 79-year, and 228 pM in 80 to 96-year olds (p < 0.01). We conclude that the sex differences in insulin levels are explained by differences in body habitus and post-load glucose levels, but that insulin levels decline with age per se.

Longitudinal evaluation of serum androgen levels in men with and without prostate cancer

Androgens are thought to play a role in the pathogenesis of prostate cancer. We evaluated androgen levels in 3 age-matched groups of men who were part of the Baltimore Longitudinal Study of Aging: 1) 16 men with no prostatic disease by urologic history and exam (control group); 2) 20 men with a histologic diagnosis of benign prostatic hyperplasia (BPH) who had undergone simple prostatectomy; and 3) 20 men with a histologic diagnosis of prostate cancer (16 with local/regional cancer, and 4 with metastatic cancer). Luteinizing hormone (LH), total testosterone (T), and free T were measured on stored AM sera by radioimmunoassay (RIA). Free T was also calculated from the measured concentrations of total T and sex hormone binding globulin (SHBG). The median number of repeated sex steroid measurements ranged from 6-9 over a period from 7-25 years prior to the diagnosis of prostate disease. There were no significant differences in age-adjusted LH, total T, SHBG, or calculated free T levels among the groups at 0-5, 5-10, and 10-15 years before diagnosis. These data suggest that there are no measurable differences in serum testosterone levels among men who are destined to develop prostate cancer and those without the disease.

Behavioral treatment of cocaine-dependent pregnant women and TB-exposed patients

Health-compromised drug-dependent patients require specialized treatment that addresses both drug use and health risks. This preliminary study examines the efficacy of a contingency management procedure (shaping) on decreasing cocaine use and increasing compliance with the prescribed treatment regimens in two health-compromised cocaine-dependent populations: (i) tuberculin (TB) exposed patients (n = 5) and (ii) pregnant women (n = 7). A multiple-baseline across-subjects design was used. There were no contingencies on cocaine use during baseline. During the contingent phase, patients received a monetary reinforcer for (a) successive decreases in the quantity of cocaine and (b) cocaine-free samples. They received a weekly reinforcer if all samples per week met criteria for (a) or (b). During the contingent phase, there was a significant decrease in cocaine metabolite levels and an increase in cocaine-free samples in both populations, with a more robust effect in the TB-exposed group. There was an increase in compliance with prenatal visits among the pregnant women during the contingent phase. Implications for health care are discussed.

Cessation of cocaine use during pregnancy: a preliminary comparison

This preliminary study examined differences between cocaine-dependent pregnant women who received "baseline" drug treatment (N = 13) and those requiring additional "intensive" treatment (N = 9). Baseline drug treatment consisted of weekly individual counseling sessions. Intensive treatment, in the form of contingency management procedures, was added for patients who showed no reduction in cocaine use during the first 4 weeks of treatment. There were no differences between the two groups in terms of demographic and pregnancy characteristics or history of cocaine use. Significantly more patients in the baseline treatment group were cocaine-free at intake and had a higher rate of compliance with scheduled prenatal clinical visits. These findings may indicate a decision to cease cocaine use prior to entering treatment, and a high degree of motivation to remain drug-free. Despite the small sample size, the finding that a substantial proportion of cocaine-dependent pregnant women remain cocaine-free during treatment is encouraging.

Body mass index and mortality in Seventh-day Adventist men. A critique and re-analysis

The aim of this work was to determine if the relationship between weight-adjusted-for-height (expressed as body mass index or BMI) using the BMI-at-entry and age-at-entry as opposed to BMI at entry and age-at-event (i.e. death, loss to follow-up, or end of the study) would alter the results previously reported from a population of Seventh-day Adventist men. The subjects were 8828 non-smoking, non-drinking Seventh-day Adventist men, ages 30-89 and older on entry, mean follow-up 15 years (maximum 26 years). The BMI and age reported by subjects when they were enrolled into the study were used to calculate the relationship between BMI and mortality. Mortality rates in each of five BMI quintiles were computed by dividing the number of deaths in each quintile by the number of person years of follow-up in the quintile. Rate ratios were computed by dividing each mortality rate by the rate in the reference quintile. The mortality rate ratios were then adjusted for the age difference between each quintile and the reference quintile. Calculations based upon age-at-enrollment rather than 'age-at-event' (as used in the original paper) demonstrate no increase in mortality until a BMI of 27.5 kg/m2 or greater is reached rather than a progressive increase in mortality with increasing BMI.

High plasma vitamin C associated with high plasma HDL- and HDL2 cholesterol

High plasma vitamin C may lower risk of cardiovascular disease as indicated by direct association with plasma high-density-lipoprotein (HDL) cholesterol and HDL2 cholesterol. Plasma lipids and vitamin C were determined in 316 women and 511 men (aged 19-95 y). After adjustment for age, sex, obesity, and smoking, plasma vitamin C was directly associated with HDL- (P = 0.01) and HDL2 cholesterol (P = 0.0002). When men and women with diseases that might affect lipids were excluded, associations between plasma vitamin C and HDL- and HDL2 cholesterol persisted, though the relationships were strongest in older men. Comparisons of diets in a subset (n = 485) who completed 7-d diet records were made. Total fat, saturated fatty acids, energy from fat, and cholesterol intakes were not associated with plasma vitamin C. Mean intakes of vitamin C were well above recommended dietary allowances. These findings suggest that high plasma concentrations of vitamin C may lower atherogenic risk.

A direct radioimmunoassay for free progesterone in saliva

The direct radioimmunoassay using iodinated tracer (125I-HIS-3CMO) has been developed for the determination of salivary progesterone of healthy volunteers with regular menstrual cycles. Lack of significant diurnal variation either in the follicular or luteal phase indicated that collections of saliva could be tailored to the need of individuals making the study somewhat easier. Salivary progesterone has shown to correlate significantly with free serum progesterone reflecting the unbound biologically active progesterone fraction in blood. Moreover, salivary progesterone concentration ranges are similar to those found in other studies. Our findings indicated that determination of progesterone in saliva could be used in place of serum or plasma. Since firstly, it is non-invasive, easy for sample collection and a stress-free technique. Secondly, it is much more accurate in prediction of corpus luteum function and ovulation than the basal-body temperature or endometrial biopsy or other clinical predictors currently in use. Finally, determination of daily salivary progesterone levels throughout the menstrual cycle may be advantageously employed as a non-invasive serial sampling technique for the assessment of corpus luteum and ovarian functions.

The sagittal waist diameter and mortality in men: the Baltimore Longitudinal Study on Aging

The study objective was to determine the relationship between the abdominal sagittal diameter (waist depth) and subsequent mortality. This was a prospective study carried out in 981 male participants of the Baltimore Longitudinal Study on Aging which is a prospective study at the National Institute on Aging in Baltimore. The main outcome measures of the study were total and cause-specific mortality occurring during 17,529 person-years. The men were divided by age (cut-off point 55 years) at the start of follow-up. All-cause and coronary heart disease mortality rates (adjusted for age, height and body mass index) increased with increasing sagittal diameter in the younger group but not in the older group. No significant relationship was observed between the sagittal diameter and cancer mortality. Body mass index, skinfolds and waist/hip ratio were not significantly related to any of the endpoints studied. The increased risk of mortality with increasing sagittal diameter was somewhat stronger when the first ten years of follow-up were excluded and was more pronounced at lower levels of risk factors such as serum cholesterol, serum triglycerides, plasma glucose and diastolic blood pressure and in never plus ex-smokers compared to smokers. The study indicates that the abdominal sagittal diameter is a strong predictor of mortality in younger adult men independently of age, height, body mass index and conventional risk factors for mortality such as smoking, serum lipids and blood pressure. Regional adiposity may be a less strong risk factor for mortality in older men.

Long-term effects of change in body weight on all-cause mortality. A review

OBJECTIVE

To summarize published studies analyzing the effects of long-term change in body weight on all-cause mortality and have not been reported elsewhere in these proceedings.

DATA SOURCES

Thirteen reports from 11 diverse population studies, 7 from the United States and 4 from Europe.

STUDY SELECTION

All studies included a weight change period of 4 or more years, followed by a mortality assessment period of 8 or more years. All weight changes occurred in persons 17 years or older.

DATA EXTRACTION

Data from individual studies are presented as number of participants, number of deaths, ages at initial and final weight measurements, duration of the mortality follow-up period, consideration of cigarette smoking and other potential confounders, exclusion criteria, temporal separation between the weight change and mortality follow-up periods, and the association between weight change and all-cause mortality.

DATA SYNTHESIS

Results are summarized by weight change associated with the lowest mortality rate and by the effects of long-term weight loss on mortality rate.

CONCLUSIONS

Despite the diversity of the populations studied, the degree of "clinical clean-up" at entry, the techniques used to assess weight change, and the differences in analytic techniques (including consideration of potentially confounding variables), certain conclusions may be drawn. Evidence suggests that the highest mortality rates occur in adults who either have lost weight or have gained excessive weight. The lowest mortality rates are generally associated with modest weight gains.

The effect of age on insulin response and glucose utilization during four hyperglycemic plateaus

In order to evaluate the potential role of insulin insensitivity as a cause of the glucose (G) intolerance of aging, we performed 230 hyperglycemic clamps, 85 on young (Y, 24 to 39 years), 47 on middle age (M, 40 to 59 years), and 98 on old (O, 60 to 90 years) carefully screened subjects of the Baltimore Longitudinal Study of Aging. The 2-h plasma G levels on an oral glucose tolerance test (OGTT) were < 7.8 mmol/l in Y and M and < 10 mmol/l in old; the latter group was further dichotomized at 7.8 mmol/l into a "normal" group, ON, and an impaired group, OI. Four hyperglycemic plateaus were created: 3.0, 5.4, 7.9, and 12.8 mmol/l above basal. Three measures of glucose tolerance--1) G at 2 h after glucose ingestion, 2) glucose utilization, M, at each hyperglycemic plateau, and 3) glucose decay constant, K, obtained at the conclusion of each clamp--showed the best performance in the young group (Y > M = ON > OI). Despite these differences in glucose tolerance, plasma insulin responses (I) during the clamp were not significantly different except that ON < Y at the basal + 12.8 plateau (300 +/- 42 vs. 456 +/- 48 pmol/l, p < 0.01). Insulin-dependent glucose uptake, a measure of tissue sensitivity to insulin, was decreased in the old-impaired group at every plateau except the highest. We conclude that healthy, active older subjects showed moderate intolerance to oral and IV glucose and that the mechanism of this physiological aging process is most likely decreased insulin sensitivity.

An epidemiological test of the hyperinsulinemia-hypertension hypothesis

The association between hyperinsulinemia and hypertension was tested in a population of 421 men and 228 women from the Baltimore Longitudinal Study of Aging. Subjects are white, middle-class, generally healthy, community-dwelling volunteers who ranged in age from 17-95 yr. Those with disease or medications known to influence any of the studied variables were excluded from the analysis. Twenty-five percent of the subjects were borderline or hypertensive [systolic blood pressure (BP) > or = 140 or diastolic BP > or = 90 mm Hg]. Standard oral glucose tolerance tests were performed; the logarithms of the fasting insulin level and insulin area were used in the analyses. In addition, body mass index and percent body fat (from age and skinfold thickness equations) and waist hip ratio were computed. In simple correlations, systolic BP and diastolic BP were statistically significantly related to insulin levels (only 1-4% of the variance was explained). Since age, body fat, fat distribution, insulin levels, and BP were highly intercorrelated, insulin and blood pressure correlations were examined after controlling for the confounding variables. Correlations of BP and insulin levels adjusted for age, body fat, and fat distribution were entirely nonsignificant. In this large noninterventive population study, the hyperinsulinemia-hypertension hypothesis is not confirmed.

Long-term longitudinal measurements of plasma dehydroepiandrosterone sulfate in normal men

Dehydroepiandrosterone sulfate (DS) was measured by direct tritium RIA in longitudinal plasma specimens from 97 normal healthy male participants in the Baltimore Longitudinal Study of Aging. Fasting blood was collected at regular visits (approximately 1.5 yr apart) over an average 13 yr of adulthood (cumulative age range: 32-83 yr). DS was measured in 3-4 widely spaced specimens from each subject. A decline in DS was found in 65 (67%) subjects, 13 subjects (13%) showed no change, and increases were found in the 19 remaining subjects during the study period. A plot of individual data points revealed the same pattern we had obtained previously from a cross-sectional study of a different normal male population. A plot of DS values vs. age among subjects whose DS increased during the study also revealed an age-related decline. Thus, the longitudinal decrease in circulating DS, long inferred from cross-sectional data, is confirmed for normal men in the present study. A more detailed study of every specimen collected during the study period from 12 of the Baltimore Longitudinal Study of Aging subjects (4 whose values tended to be low, 4 whose values tended to be high, and 4 whose values were near the mean) failed to reveal any patterns of variation that could be correlated with changes in life circumstances, health status, or any other discernible factors. Hence, the wide variability seen in DS among individuals within normal populations remains unexplained.

Fasting respiratory exchange ratio and resting metabolic rate as predictors of weight gain: the Baltimore Longitudinal Study on Aging

The authors followed 775 men (aged 18-98 years) participating in the Baltimore Longitudinal Study in Aging for an average of ten years. Resting metabolic rate and fasting respiratory exchange ratio (RER) were measured by indirect calorimetry on their first visit and related to subsequent weight change. Deviations from the predicted value of resting metabolic rates (predicted from their estimated fat-free mass) were calculated. Average weight change was 0.07 kg (s.d. 6.4 kg); 122 men (15.3%) gained more than 5 kg and 40 (5.2%) more than 10 kg during the follow-up. After adjustment for initial age, body mass index, fat-free mass, and duration of follow-up, RER, but not RMR or deviations from predicted RMR, was positively related to weight change (P less than 0.001). Major weight gain (from at least 5 kg to at least 15 kg) was related to initial RER in non-obese men only (initial body mass index less than 25 kg/m2). From Cox proportional hazard regression analyses the adjusted relative risk of gaining 5 kg or more in initially non-obese men with a fasting RER of 0.85 or more was calculated to be 2.42 (95% confidence interval: 1.10-5.32) compared to men with a fasting RER less than 0.76. It was concluded that a relatively high fasting RER is a weak but significant predictor of substantial weight gain in non-obese white men.

Salivary gland function and glucose metabolic status

To study the relationship between glucose metabolic status and salivary gland function in different-aged persons, subjects with diabetes mellitus (DM = 11), impaired glucose tolerance (IGT = 26), and controls (n = 26), aged 24 to 93, were examined in the oral physiology component of the Baltimore Longitudinal Study of Aging. All were generally healthy (except DM) and nonmedicated. The controls and subjects with IGT were classified using World Health Organization criteria, and diabetic status was assessed using Hb1Ac levels. Unstimulated and 2% citrate-stimulated parotid and submandibular salivary flow rates were collected, and subjective responses to questions about salivary hypofunction were evaluated. No statistically significant differences were observed between the three groups, nor between young and old subjects with altered glucose metabolism. These findings suggest that among well-controlled individuals with altered glucose metabolism, salivary gland function is not significantly impaired.

Glucose tolerance in women: the effects of age, body composition, and sex hormones

OBJECTIVE

To determine the separate and interactive effects of age, phase of the menstrual cycle, menopausal hormone status, body fat mass, and regional fat distribution on glucose tolerance in healthy women.

DESIGN

Retrospective study.

SETTING

The Baltimore Longitudinal Study of Aging.

PATIENTS

Two hundred sixty healthy women aged 22-89 years.

MEASUREMENTS

Plasma levels of estradiol and progesterone, body mass index (BMI), waist-to-hip ratio (WHR), and plasma glucose values in the fasting state (FPG) as well as 120 minutes after 40 gm/m2 of oral glucose (G120) were measured for each participant.

RESULTS

We found a progressive decline in oral glucose tolerance of 0.4 mM (6.7 mg/dL)/decade at G120) in women from early to late adult years, with no relationship to phase of the menstrual cycle and no abrupt change associated with the menopause. Multiple regression analysis revealed significant, independent effects of BMI and WHR on FPG and G120. The influence of age (P less than 0.01) on G120 was stronger than that of the BMI or WHR (P less than 0.05). There was no significant relationship between the levels of endogenous sex hormones and glucose tolerance after adjustments for age, BMI, and WHR. However, women taking oral contraceptives, but not those receiving postmenopausal replacement therapy, did exhibit mildly elevated G120 values.

CONCLUSIONS

Age per se, and to a lesser extent BMI and WHR, but not levels of endogenous sex steroids, contribute to the physiological decline in glucose tolerance in older women.

Cholesterol as a risk factor for coronary heart disease in elderly men. The Baltimore Longitudinal Study of Aging

In order to explore the relationship of cholesterol to coronary heart disease (CHD), defined as angina pectoris, myocardial infarction, and sudden coronary death, in older men, a group of 1052 men, participants in the Baltimore Longitudinal Study on Aging, were examined. Subjects were stratified into three age groups, 28 to 64, 65 to 74, and 75 to 97 years old. In all three age groups, cholesterol was a significant risk factor for CHD. In the oldest age group (n = 250), the relationship between cholesterol and risk was linear (P = .003) as opposed to younger age groups where the relationship was exponential. This study extends the age range in which hypercholesterolemia has been shown to be associated with CHD to include the 75- to 97-year range.