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Biomedical subjects

M C Sadler

Publications and source records attributed to M C Sadler.

12 recordsLinked to original sources
PubMed1999

Seven-year changes in physical fitness, physical activity, and lipid profile in the CARDIA study. Coronary Artery Risk Development in Young Adults.

PURPOSE: To relate seven year changes in physical fitness and physical activity in the young adult population to changes in the plasma lipid profile and to examine the influence of weight change on those relationships. METHODS: The participants in this observational study were the 1777 black and white men and women, ages 18-30 at entry into the Coronary Artery Risk Development in Young Adults (CARDIA) cohort, who completed a symptom-limited graded treadmill exercise test and had an overnight fasting blood draw at both the Baseline (1985-86) and Year 7 (1992-93) exams. CARDIA, a longitudinal study of the relationships of lifestyle and physiological variables to the development of coronary heart disease risk factors, consists of population-based cohorts in Birmingham, Alabama, Minneapolis, Minnesota and Chicago, Illinois and a cohort recruited from the membership of a large, pre-paid health care plan, broadly representative of the population, in Oakland, California. RESULTS: All race/gender groups experienced mean decreases in physical fitness and self-reported physical activity and increases in weight. Decreased fitness was associated with decreased high density lipoprotein-cholesterol (HDL-C), and conversely, increased fitness was associated with increased HDL-C. The correlation coefficients of change in fitness with change in HDL-C ranged from 0.17 in white men and black women to 0.24 in white women (P < 0.001 for all race/gender groups). Change in fitness was minimally correlated with change in low density lipoprotein-cholesterol (LDL-C) in all groups (r ranged from -0.09 in black women to -0.20 in white women), triglycerides (TG) in men and white women (r ranged from -0.10 to -0.15), and total cholesterol (TC) in white men and women (r = -0.11 and -0.15, respectively). The magnitude of these correlations was further reduced with adjustment for weight change. Correlations between change in activity and change in lipid and lipoprotein values were generally weak or nonexistent, except for the suggestion of a small, direct relationship with change in HDL-C in black and white women (r = 0.14 and r = 0.11, respectively). All of the weight change adjusted correlations were essentially unaffected by further adjustment for baseline fitness or activity and other covariates. CONCLUSIONS: Decreased fitness during young adulthood is associated with unfavorable changes in lipid profile, explained mostly by increased weight. Lack of association between change in activity and change in lipid profile observed in this study may be due, in part, to imprecision of activity measurement.

Adolescent↗
PubMed1997

The safety of transurethral prostatectomy: a cohort study of mortality in 9,416 men.

PURPOSE: We assessed the mortality rate from transurethral resection of the prostate. MATERIALS AND METHODS: From 1976 to 1984, 4,708 patients undergoing transurethral resection of the prostate for benign prostatic hypertrophy (BPH) were compared retrospectively to an age-matched group of 4,708 randomly selected Kaiser Permanente Medical Care Program members not undergoing surgery. The risk of mortality associated with transurethral resection of the prostate relative to no surgery was determined using proportional hazards models. RESULTS: The relative risk for surgery versus no surgery for the total group was 0.88 (95% confidence interval 0.82 to 0.95). Similarly, the results for each 5-year age group demonstrated a relative risk of 0.77 to 0.95. CONCLUSIONS: This cohort study showed no excess mortality for patients undergoing transurethral resection of the prostate compared to age-matched comparison subjects randomly selected from health plan members who did not undergo surgery. Information from this study about the safety of transurethral resection of the prostate can be shared with patients when discussing treatment options.

Aged↗
PubMed1997

5 alpha-reductase activity and prostate cancer: a case-control study using stored sera.

We report a nested case-control study of serum biomarkers of 5 alpha-reductase activity and the incidence of prostate cancer. From a cohort of more than 125,000 members of the Kaiser Permanente Medical Care Program who underwent multiphasic health examinations during 1964-1971, we selected 106 incident prostate cancer cases. A control was pair matched to each case on age, date of serum sampling, and clinic location. Serum levels of total testosterone, free testosterone, androsterone glucuronide, and 5 alpha-androstane-3 alpha,17 beta androstanediol glucuronide (3 alpha-diol G) were measured on the stored samples and scored as quartiles. Potential confounders included alcohol, smoking, and body mass index. The adjusted odds ratios and 95% confidence intervals for a one quartile score increase were 1.00 (0.75-1.34) for total testosterone, 1.14 (0.86-1.50) for free testosterone, 1.13 (0.84-1.53) for androsterone glucuronide, and 1.16 (0.86-1.56) for 3 alpha-diol G. A limitation of this study is that there are two different 5 alpha-reductase isoenzymes, only one of which is expressed in high levels within the prostate, yet both of which may affect serum biomarkers. Since the two isoenzymes are encoded on different chromosomes, variation in one would act as an independent source of measurement error in any analysis of serum biomarker effects of the other. Consequently, the odds ratios may be underestimated and the study, although negative, cannot exclude the previously hypothesized possibility that a positive relationship between intraprostatic 5 alpha-reductase activity and prostate cancer may exist. A clinical trial to test this hypothesis is under way.

Aged↗
PubMed1995

Mentholated cigarette use and lung cancer.

BACKGROUND: Menthol combustion produces carcinogenic compounds such as benzo[a]pyrenes. Mentholated cigarettes are much more commonly smoked by black individuals than by white individuals. The incidence of lung cancer is much higher (60%) in black men than in white men, but it differs little by race in women. We examined the association of mentholated cigarette use with lung cancer in men and women because mentholated cigarette use could help to explain the higher incidence rate of lung cancer in black men than in white men. METHODS: The study population consisted of 11,761 members of the Northern California Kaiser Permanente Medical Care Program, Oakland (5771 men and 3990 women), aged 30 to 89 years, who underwent a multiphasic health checkup in 1979 through 1985 and reported that they were current cigarette smokers who had smoked for at least 20 years. Data were collected about current cigarette brand, duration of mentholated cigarette use, and other smoking characteristics. Follow-up for incident lung cancer cases (n = 318) was carried out through 1991. RESULTS: The relative risk of lung cancer associated with mentholation compared with nonmentholated cigarettes was 1.45 in men (95% confidence interval, 1.03 to 2.02) and it was 0.75 in women (95% confidence interval, 0.51 to 1.11), adjusted for age, race, education, number of cigarettes smoked per day, and duration of smoking. Further adjustment for tar content and self-reported smoking intensity characteristics did not substantially alter the estimate of relative risk. A graded increase in risk of lung cancer with increasing duration of mentholated cigarette use was present in men. CONCLUSION: This study suggests that there is an increased risk of lung cancer associated with mentholated cigarette use in male smokers but not in female smokers.

Adult↗
PubMed1992

Reoperation and mortality after surgical treatment of benign prostatic hypertrophy in a large prepaid medical care program.

The incidence of reoperation and mortality after prostatectomy was studied in 8,219 men who underwent surgical treatment for benign prostatic hypertrophy between 1976 and 1987 while they were members of the Kaiser Permanente Medical Care Program, Northern California Region. The vast majority (94.5%) received transurethral prostatectomy (TURP). The cumulative 8-year probability of a second prostatectomy was 7.6% after TURP and 2.1% after open prostatectomy. The risk of mortality associated with transurethral prostatectomy relative to open prostatectomy was 1.6 (95% confidence interval 1.2, 2.1) 8 years postsurgery. The increased risk of mortality associated with transurethral prostatectomy was most prominent during the first 5 years postsurgery (relative risk 1.8, 95% confidence interval 1.3, 2.5) and declined to 1.1 (95% confidence interval 0.8, 1.6) for deaths occurring after the first 5 years. The finding of an increased risk of mortality associated with transurethral prostatectomy is consistent with other studies and is unexplained.

Aged↗
PubMed1991

Incidence of surgically treated benign prostatic hypertrophy and of prostate cancer among blacks and whites in a prepaid health care plan.

The incidence of surgically treated benign prostatic hypertrophy and of prostate cancer was examined to December 1987 in 14,897 men (2,175 blacks and 12,722 whites) who received multiphasic health checkups during 1971-1972 while members of the Kaiser Permanente Medical Care Program (San Francisco-Oakland, California). Prostate cancer incidence was higher in blacks than in whites for all age groups (age-adjusted relative risk (RR) = 1.8, 95% confidence interval (CI) 1.4-2.3). The incidence of benign prostatic hypertrophy was somewhat higher in blacks than in whites until age 65 years, after which it was higher in whites. In contrast to the risk of prostate cancer, the age-adjusted risk of benign prostatic hypertrophy was the same for blacks as for whites (RR = 1.0, 95% Cl 0.8-1.2).

Adult↗
PubMed1991

Vasectomy and the risk of prostate cancer in a cohort of multiphasic health-checkup examinees: second report.

The relationship of vasectomy to prostate cancer was studied in 5,119 men men with a self-reported history of vasectomy, identified at multiphasic health checkups undergone during 1977-82 while members of the Northern California Kaiser Permanente Medical Care Program. Three unvasectomized comparison subjects were identified for each vasectomized man, matched for age, race, marital status, and date and location of the examination. Follow-up for incident prostate cancer was conducted for a mean length of 6.8 years. The relative risk of prostate cancer associated with vasectomy was 1.0 (95% confidence interval = 0.7 - 1.6); the relative risk was approximately one, regardless of length of interval (less than 10 years, 10-20 years, more than 20 years) between vasectomy and multiphasic health checkup or the age at vasectomy (less than 40 years vs more than 40 years). These data support earlier findings reported in this study group of the lack of an association of vasectomy with subsequent risk of prostate cancer.

Adult↗
PubMed1991

Risk factors for surgically treated benign prostatic hyperplasia in a prepaid health care plan.

The relationship of age, medical history, personal habits, and urologic symptoms to the incidence of surgically treated benign prostatic hyperplasia (BPH) was studied in a cohort of 16,219 men, aged forty years and over, who received multiphasic health checkups (MHCs) during 1971 and 1972 in Oakland or San Francisco while members of the Northern California Kaiser Permanente Medical Care Program, a large prepaid health care program. Follow-up was carried out for surgically treated BPH from the date of the MHC to the date of the earliest of the following: surgery for BPH (n = 1,027); incidence of prostate cancer (n = 329), bladder cancer (n = 119), or both (n = 10); other prostate surgery (n = 5); death (n = 2,525); membership termination (n = 4,235); or December 31, 1987 (n = 7,969). The mean length of follow-up was twelve years. In multivariate analysis utilizing the Cox proportional hazards model, the following characteristics were positively associated (p less than 0.05) with risk of surgically treated BPH: age, low body mass index, nonsmoking (vs. current smoking), urine pH greater than 5, history of kidney x-ray and of tuberculosis, and each of five urologic symptoms (dysuria, loss of bladder control, trouble starting urination, nocturia, slow urine stream). The risk of BPH associated with obstructive urologic symptoms decreased markedly with age. Some of these findings are consistent with those from other studies (age, nonsmoking), while others (high urine pH, history of tuberculosis) are new and should be examined in other study populations.

Adult↗
PubMed1986

Mixed function oxidase activity in the harbour seal (Phoca vitulina) from Sable Is., N.S.

One adult male, eight pups (including two full term foetuses) and nine adult female harbour seals (Phoca vitulina) were analysed for indices of mixed function oxidase (MFO) activity. MFO activity was present in liver samples, but was at or below detection limits in samples of kidney, lung and pancreas. Hepatic ethoxyresorufin O-de-ethylase and benzo[a]pyrene hydroxylase activities were similar to those reported in other seals and in other mammals. Cytochromes P-450 and b5 concentrations were slightly lower than those observed in other mammals. MFO activities in newborn pups and foetuses were significantly lower than those in adult females. No qualitative differences in cytochrome P-450 isozyme distribution between foetal and adult samples could be discerned by electrophoresis.

Animals↗