The prostate-specific antigen (PSA) test, a widely used screening tool for detecting enlarged prostate and prostate cancer, may be less accurate in overweight men, report researchers from the University of Texas Health Science Center.1 The study warns that doctors could miss this dangerous cancer in obese men.
PSA is made by normal prostate cells and is measured in the blood, with levels of 4.0 or lower usually indicating that no cancer is present. Heavier men have a 33% higher risk of prostate cancer, tend to be diagnosed when their cancer is more advanced, and thus are at higher risk of dying from it.
In a study examining nearly 3,000 men with no prostate cancer over three years, researchers found that more obese men had lower PSA levels. Morbidly obese men had PSA levels that were about 30% lower than men of normal weight.1 Doctors believe that obese men produce more estrogen, which drives down testosterone levels and could affect the cells that produce PSA. Although estrogens historically have been used to treat prostate cancer, more recent findings suggest that estrogens may induce aberrant growth and neoplastic transformation in the prostate.2
PSA screening is far from foolproof. The New England Journal of Medicine last year reported that men with normal PSA values actually had cancer 15% of the time, and that two thirds of those men with cancer had aggressive cases.3
Prostate cancer detection may therefore be delayed in overweight or obese men, the investigators noted, and doctors may need to be especially vigilant when evaluating these patients. Digital rectal exams may provide an additional screening tool for prostate cancer.
—Elizabeth Wagner, ND
1. Baillargeon J, Pollock BH, Kristal AR, et al. The association of body mass index and prostate-specific antigen in a population-based study. Cancer. 2005 Jan 24.
2. Ho SM. Estrogens and anti-estrogens: key mediators of prostate carcinogenesis and new therapeutic candidates. J Cell Biochem. 2004 Feb 15;91(3):491-503.
3. Thompson IM, Pauler DK, Goodman PJ, et al. Prevalence of prostate cancer among men with a prostate-specific antigen level < or =4.0 ng per milliliter. N Engl J Med. 2004 May 27;350(22):2239-46.
Chromium, a trace mineral that is often deficient in adults, may help to prevent or treat metabolic problems, including obesity, glucose intolerance, and unhealthy lipid profiles, according to Georgetown University researchers. The investigators report that supplementation with niacin-bound chromium, or ChromeMate®, improved blood sugar and lipid measures in volunteers.*
Although chromium is easily obtained through diet and supplements, a significant number of adults are unknowingly deficient, and no test exists to make the diagnosis. The appearance of metabolic syndrome may be the first sign of chromium deficiency. In the body, chromium improves the sensitivity of insulin receptors, helping to promote optimal metabolism of sugars.
In this double-blind study, volunteers received 300 mcg per day of niacin-bound chromium or placebo for three months. At the trial’s end, the supplemented group had lower fasting glucose and triglyceride levels than the control group, and also had lower levels of glycosylated hemoglobin, or hemoglobin A1c, a measure of long-term blood sugar control. The niacin-bound chromium supplement was well tolerated, with no adverse effects reported.
Niacin-bound chromium supplementation may thus reduce the risk for glucose intolerance, prevent the progression of glucose intolerance to frank diabetes, improve glucose control in diabetics, and assist in managing elevated triglyceride levels.
—Linda M. Smith, RN
* Yasmin T, Shara M, Bagchi M, Preuss HG, Bagchi D. Toxicological assessment of a novel niacin-bound chromium, known to ameliorate the symptoms of metabolic syndromes. Journal of the American College of Nutrition, 45th Annual Meeting, abs 77, October;76(2):272-5.
Abnormal hormone levels may play a role in the development of multiple sclerosis, report researchers at University La Sapienza in Italy.* The investigators measured hormone levels in 35 women and 25 men with multiple sclerosis, and in 36 people without the disease.
Women with low testosterone levels were found to have more brain tissue damage, as determined using magnetic resonance imaging. The women with multiple sclerosis had lower levels of testosterone throughout their monthly cycle compared to women who did not have the condition.
Multiple sclerosis is an inflammatory disease causing symptoms such as fatigue, numbness, and difficulties in movement, speech, and memory. Its course is marked by remissions and relapses. Multiple sclerosis affects twice as many women as men, and is significantly less active during pregnancy, suggesting that hormones influence its development. The Italian study further supports the hypothesis that sex hormones play a role in the inflammation, damage, and pathology of multiple sclerosis.
—Elizabeth Wagner, ND
* Tomassini V, Onesti E, Mainero C, et al. Sex hormones modulate brain damage in multiple sclerosis: MRI evidence. J Neurol Neurosurg Psychiatry. 2005 Feb; 76(2):272-5.