Biomedical subjects

Kenneth F Adams

Publications and source records attributed to Kenneth F Adams.

4 recordsLinked to original sources

PubMed2006

Overweight, obesity, and mortality in a large prospective cohort of persons 50 to 71 years old.

BACKGROUND: Obesity, defined by a body-mass index (BMI) (the weight in kilograms divided by the square of the height in meters) of 30.0 or more, is associated with an increased risk of death, but the relation between overweight (a BMI of 25.0 to 29.9) and the risk of death has been questioned. METHODS: We prospectively examined BMI in relation to the risk of death from any cause in 527,265 U.S. men and women in the National Institutes of Health-AARP cohort who were 50 to 71 years old at enrollment in 1995-1996. BMI was calculated from self-reported weight and height. Relative risks and 95 percent confidence intervals were adjusted for age, race or ethnic group, level of education, smoking status, physical activity, and alcohol intake. We also conducted alternative analyses to address potential biases related to preexisting chronic disease and smoking status. RESULTS: During a maximum follow-up of 10 years through 2005, 61,317 participants (42,173 men and 19,144 women) died. Initial analyses showed an increased risk of death for the highest and lowest categories of BMI among both men and women, in all racial or ethnic groups, and at all ages. When the analysis was restricted to healthy people who had never smoked, the risk of death was associated with both overweight and obesity among men and women. In analyses of BMI during midlife (age of 50 years) among those who had never smoked, the associations became stronger, with the risk of death increasing by 20 to 40 percent among overweight persons and by two to at least three times among obese persons; the risk of death among underweight persons was attenuated. CONCLUSIONS: Excess body weight during midlife, including overweight, is associated with an increased risk of death.

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PubMed2005

Soy protein containing isoflavones does not decrease colorectal epithelial cell proliferation in a randomized controlled trial.

BACKGROUND: Soy isoflavones have numerous biological properties that suggest that they may protect against colorectal cancer. Colorectal epithelial cell proliferation has been used extensively as an intermediate endpoint biomarker for colorectal neoplasia. OBJECTIVE: We tested the hypothesis that supplementation with soy protein containing isoflavones decreases colorectal epithelial cell proliferation. DESIGN: A 12-mo randomized intervention was conducted in men and women aged 50-80 y with recently diagnosed adenomatous polyps. One hundred fifty participants were enrolled and randomly assigned to an active treatment group (58 g protein powder/d containing 83 mg isoflavones/d; +ISO) or a control group (ethanol-extracted soy-protein powder containing 3 mg isoflavones; -ISO). Biopsy specimens from the cecum, sigmoid colon, and rectum were collected at baseline and at the 12-mo follow-up. Ki-67 antibody immunohistostaining was used to detect cell proliferation. One hundred twenty-five participants completed the study, and proliferation was measured in the first 91 who completed the study. RESULTS: In the sigmoid colon, cell proliferation increased by 0.9 (95% CI: 0.09, 1.9) labeled nuclei per crypt more (11%) in the +ISO group than in the -ISO group over the 12-mo intervention, which was opposite the direction predicted. The number of labeled nuclei per 100 mum crypt height also increased more in the +ISO than in the -ISO group. In the cecum and sigmoid colon, but not in the rectum, the proliferation count increased as the serum genistein concentration increased. Proliferation distribution and crypt height were not changed by treatment at any site. CONCLUSIONS: Supplementation with soy protein containing isoflavones does not reduce colorectal epithelial cell proliferation or the average height of proliferating cells in the cecum, sigmoid colon, and rectum and increases cell proliferation measures in the sigmoid colon.

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PubMed2004

Soy isoflavones do not modulate prostate-specific antigen concentrations in older men in a randomized controlled trial.

Mortality rates for prostate cancer are low in Asia but high in the West. One explanation is the high level of soy consumption in Asia. Soy isoflavones reduce prostate tumor growth in many, but not all, animal models. Elevated levels of serum prostate-specific antigen (PSA) are a marker of prostate tumor growth. Our objective was to determine whether 12-month soy isoflavone supplementation would alter serum PSA concentrations in healthy, older men. The parent study was a double-blinded, parallel-arm, randomized trial in which participants were assigned to consume either a soy protein drink providing 83 mg/day isoflavones (+ISO) or a similar drink with isoflavones removed (-ISO). Participants in the parent study were 85% men. Of the 128 men enrolled in the trial, 112 completed. These men were later contacted for consent to allow their stored sera to be analyzed for PSA and 81 men consented. We measured PSA in serum collected at 0 and 12 months using a commercial radioimmunometric assay. Serum PSA concentrations increased in both groups over the 12-month intervention, but the changes were similar: Geometric mean PSA concentration increased 0.5% more in the +ISO group than in the -ISO group (P = 0.94; 95% confidence interval = -17.3 to 22.2). The proportion of participants having a serum PSA velocity greater than 1 ng/ml/year was similar in the +ISO and -ISO groups (17.6% versus 12.8%; P = 0.54). We found no evidence that a 12-month 83 mg/day isoflavone treatment alters serum PSA concentration or velocity in seemingly healthy men aged 50-80 years.

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PubMed2003

Soy isoflavones do not modulate circulating insulin-like growth factor concentrations in an older population in an intervention trial.

Insulin-like growth factors (IGF) are essential for normal growth and maintenance of lean muscle mass; however, high insulin-like growth factor-I (IGF-I) and low IGF binding protein-3 (IGFBP-3) levels are also associated with several cancers. To test the hypothesis that long-term soy isoflavone supplementation decreases circulating IGF-I concentrations, we conducted a controlled, parallel-arm, double-blind intervention study with 150 participants (85% men), 50-80 y old. Participants were randomly assigned to consume a soy beverage powder daily for 12 mo. The active treatment group (+ISO) received soy protein containing 83 mg isoflavones, whereas the comparison group (-ISO) received soy protein containing 3 mg isoflavones. Serum IGF-I and IGFBP-3 were measured by ELISA. Mean change in serum IGF-I concentrations was similar in the two groups (+1.4 nmol/L in +ISO, +1.2 nmol/L in -ISO; P = 0.74, 95% confidence interval -1.1, +1.5 nmol/L for the 0.21 nmol/L difference between groups), indicating no effect of the isoflavone intervention. Similarly, the changes in IGFBP-3 and the IGF-I/IGFBP-3 ratio were similar in both groups, again showing no effect of +ISO treatment. A 12 mo, 83 mg/d soy isoflavone intervention did not modulate serum IGF in an older, mostly male population.

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