Overweight, Excessive Insulin Secretion and Higher Prostate Cancer Mortality

This time, a men's health topic. A new study from Boston, published in a Lancet Oncology Early Online Publication on October 6, 2008, presented evidence that being overweight, and/or having excessive insulin secretion (as indicated by a high plasma C-peptide concentration), increases the risk for death in prostate cancer.

The study reported on 2546 men who are participants in a Physicians' Health Study of 24 years, and who developed prostate cancer. Patients who started off being overweight or obese a higher risk for death from prostate cancer, compared to normal-weight men Patients who were both obese and who also had high insulin levels had four times the risk compared to controls. The authored cautioned "Further studies are now needed to confirm these findings."

The study confirms previous evidence regarding the relationship between prostate cancer mortality and obesity. Although diabetes is associated with lower risk of prostate cancer, the new study suggests a correlation to high secretion of insulin, which is a characteristic of insulin resistance. Insulin resistance is common in overweight and obese people. Despite the complex relationship, being overweight or obese appears to have an all in all bad effect on those who develop prostate cancer.

References:

Ma J, Li H, Giovannucci E, Mucci L, Qiu W, Nguyen PL, Gaziano JM, Pollak M, Stampfer MJ. Prediagnostic body-mass index, plasma C-peptide concentration, and prostate cancer-specific mortality in men with prostate cancer: a long-term survival analysis. Lancet Oncology Early Online Publication. October 6, 2008. (Abstract)


Smith MR, Bae K, Efstathiou JA, Hanks GE, Pilepich MV, Sandler HM, Shipley WU. Diabetes and mortality in men with locally advanced prostate cancer: RTOG 92-02. J Clin Oncol. 2008 Sep 10;26(26):4333-9. [PMID: 18779620] (Abstract)

Low Serum Vitamin D and Hip Fracture Risk

A new study published in the Annals of Internal Medicine showed that low vitamin D levels in the blood are associated with an increased risk of hip fracture in postmenopausal women. The study included 800 individuals (400 who had hip fractures, matched with 400 women who did not have hip fractures). Hip fracture risk was highest among women who had the lowest levels of vitamin D in their serum.

As we know, there is an association between low vitamin D levels and obesity. Also, after bariatric surgery, there is a possibility of developing low serum levels if supplementation is not taken regularly. Those were discussed before here and here.

Reference:

Cauley JA, LaCroix AZ, Wu L, Horwitz M, Danielson ME, Bauer DC, Lee JS, Jackson RD, Robbins JA, Wu C, Stanczyk FZ, LeBoff MS, Wactawski-Wende J, Sarto G, Ockene J, Cummings SR. Serum 25-Hydroxyvitamin D Concentrations and Risk for Hip Fractures. Ann Intern Med. 2008 August;149:242-250. (Summary for Patients, Abstract)

Oxalate Kidney Damage

Make sure you stay hydrated, and take precautions to help preventing oxalate kidney stones. Those precautions can also help preventing a condition called "Oxalate Nephropathy"

Some definitions:

Nephropathy: A disease or an abnormality affecting the kidneys

Oxalate: A chemical that, when combined with calcium, can form calcium oxalate stones (usually called oxalate stones)

Oxalate Nephropathy: An abnormal condition of the kidneys that results from precipitation of calcium oxalate crystals in the kidneys.

Oxalate nephropathy can lead to kidney failure. Oxalate nephropathy leading to kidney failure has been previously reported in a patient who took a high dose of Orlistat (the active ingredient in Xenical and Alli). That one reported patient had, before taking Orlistat, an abnormal kidney (chronic kidney disease from hypertension and possibly diabetes).

This time, I am commenting on a new article that appeared in the Clinical Journal of the American Society of Nephrology which reported cases of oxalate nephropathy complicating Roux-en-Y gastric bypass in patients who had, prior, an underlying mild chronic kidney disease from obesity, hypertension and /or diabetes.

The authors identified eleven patients with oxalate nephropathy after gastric bypass. Those patients developed end-stage kidney disease. The mean age was about 61 years. All patients had a history of high blood pressure disease, and 9 had diabetes. Patients were likely to have an underlying mild chronic kidney disease from obesity, hypertension and /or diabetes. There is actually a nice summary of the effects of obesity on the kidneys in Dr. Sharma's blog. The conslusion of the study we are discussing today is that, patients with kidney disease may be at a higher risk for oxalate nephropathy after gastric bypass.

Ways to help preventing oxalate kidney stones can also help preventing oxalate nephropathy, and they were described here. Remaining hydrated in this hot weather is particularly important. Low fat intake, restricting foods rich in oxalates, taking calcium supplements, low sodium diet, and possibly considering a medication (hydrochlorothioazide) in selected patients, my all help.

References:

Nasr SH, D'Agati VD, Said SM, Stokes MB, Largoza MV, Radhakrishnan J, Markowitz GS. Oxalate Nephropathy Complicating Roux-en-Y Gastric Bypass: An Underrecognized Cause of Irreversible Renal Failure. Clin J Am Soc Nephrol. 2008 Aug 13. [PMID: 18701613] (Abstract)

Singh A, Sarkar SR, Gaber LW, Perazella MA. Acute oxalate nephropathy associated with orlistat, a gastrointestinal lipase inhibitor. Am J Kidney Dis. 2007 Jan;49(1):153-7. [PMID: 17185156] (Abstract)

Two Hundred Seventy Five Minutes per Week

A new study that is published in the Archives of Internal Medicine, reported that the commonly recommended physical activity levels (150 minutes per week) are not good enough to maintain weight loss. They concluded that 275 minutes of physical activity per week , in combination with a reduction in calorie intake, is important to maintain a weight loss of more than 10%. The study was conducted on 201 overweight and obese women with body mass index ( BMI) of 27 to 40.

The basics of achieving weight loss and maintaining a healthy weight have always been the same:

(1) Dietary management: portion control and high quality food.
(2) Increasing the activity level: by exercising, and by leading a physically active attitude during everyday normal activities.

This study validated the combined approach and, furthermore, has set a new recommendation for physical activity. Although the study is not a post-surgery study, the recommendations are valid for postoperative bariatric surgery individuals. The surgery is just a tool to achieve weight loss that cannot be achieved otherwise in a majority of people.

Reference:

Jakicic JM, Marcus BH, Lang W, Janney C. Effect of exercise on 24-month weight loss maintenance in overweight women. Arch Intern Med. 2008 Jul 28;168(14):1550-9. [PMID: 18663167] (Abstract)

Affiliations: University of Pittsburgh, Pennsylvania, Brown Medical School and The Miriam Hospital, Providence, Rhode Island.

A Food Diary Works!

Probably it is not new knowledge that recording a diary of the food intake and exercise activities does help. Now, a new study from Portland, Oregon has verified the positive outcomes of keeping a food diary. The weight loss actually doubled to 18 pounds in 20 weeks, compared to 9 pounds, by using that method. So, here is a nice simple tool that can go a long way, and that needs only a pencil and a sheet of paper. Remember, the best time to enter your food intake into your diary is right on the spot. Once you're done with the meal. For more coverage of this subject, you can go to an article in Informify News and an article in the Washington Post.

Somewhat related, is an old report published in 1992 in the New England Journal of Medicine (Abstract). It showed that, among obese individuals who repeatedly failed to lose weight despite reporting adherance to a 1200 Kcal-per-day diet, the study group underreported their actual food intake by an average of 47%, and overreported their physical activity by an average of 51%.

Stay Healthy!

Reference:

Hollis JF, Gullion CM, Stevens VJ, Brantley PJ, Appel LJ, Ard JD, Champagne CM, Dalcin A, Erlinger TP, Funk K, Laferriere D, Lin PH, Loria CM, Samuel-Hodge C, Vollmer WM, Svetkey LP; Weight Loss Maintenance Trial Research Group. Weight loss during the intensive intervention phase of the weight-loss maintenance trial. Am J Prev Med. 2008 Aug;35(2):118-26. [PMID: 18617080] (Abstract)

At what age do we stop being so active?

I wondered, at what point in our lives have we shifted from running to walking? From moving a lot to moving only if we need to? Basically, when does our moderate-to-vigorous activity level shift from the tireless running allover the place to the more adult-like style of moving when we need to? A very interesting study, published in the July 16, 2008 issue of JAMA gave some insight. The authors analyzed the data of more than 1000 children, almost half of them were boys and the other half were girls. The researchers followed their patterns of moderate-to-vigorous physical activity from age 9 to age 15. They found that at 9, the average child engaged in good 3 hours of moderate-to-vigorous physical activity, which is well more than the recommended minimum of 60 minutes per day. By age 15 years, adolescents were active at that level for only 49 minutes per weekday and 35 minutes per weekend day. Boys were more active than girls. It is well-known that decreased physical activity is an important factor in childhood obesity.

I am not sure what exactly happens. Why at some point in our lives we start walking if we don't have to run, and sit if we don't have to walk? At any rate, knowing that the transition takes place between the ages of 9 and 15, we can target that time interval and aim at keeping children engaged in organized moderate-to-vigorous activities during that period, hoping that the habit continues with them for so many more years of their lives.

Reference:

Nader PR, Bradley RH, Houts RM, McRitchie SL, O’Brien M.
Moderate-to-Vigorous Physical Activity From Ages 9 to 15 Years.
JAMA. 2008;300(3):295-305. (Abstract)

Affiliations of the authors of the reference article: Department of Pediatrics, University of California San Diego, La Jolla; Center for Applied Studies in Education, University of Arkansas, Little Rock; Statistics and Epidemiology, RTI International, Research Triangle Park, North Carolina; and Department of Human Development and Family Studies, University of North Carolina, Greensboro.

Obesity and Weight Loss Surgery in Older Age

Older age has been defined differently in different studies, as either 60 or 65 years of age.

The average body weight and BMI gradually increase during most of adult life and reach peak values at age 50–59. After the age of 60 years, the average population body weight and BMI tend to decrease. Notice that those who die prematurely because of obesity will be removed from the count of older population, and hence the lower average BMI. There is evidence that, in reality, body weight and BMI do not change, or decrease only slightly, in older people. In persons who are more than 80 years of age, obesity is about one-half that observed in the age group of 50–59. As you may see, this is another evidence that the chances that a morbidly obese patient survive through the age 80 are markedly diminished.

How about weight loss in older age? Well, we have to be very careful reading the data, because it is very easy to jump into the wrong conclusions. Several studies evaluated the relationship between weight loss and mortality in older age. Population data from all studies found that losing weight or experiencing weight variability in older age was correlated with higher mortality compared with those whose weight did not change on the average. But read carefully, because the studies did not show if the weight changes were intentional or unintentional. Older patients may lose weight, without intending to, because of serious health problems, terminal disease, or dementia. So, it is no wonder if weight loss on the average is associated with higher mortality, if the population includes those who did not intend to lose weight. Indeed, a study from the Royal Free and University College Medical School, London, England, concluded that intentional weight loss was associated with a significant reduction in mortality in markedly overweight men. The data also suggested that the earlier the intervention, the greater the chance of benefit. So, older patients can benefit from the health advantages of losing some extra weight. Another statistical twist for the mathematically inclined, is that obese patients who survive through older years represent already a pre-selected subgroup that has already defeated the fatal effects of obesity, and their survival represents selection bias, skewing the statistics in favor of better health for higher BMIs. However, it is hard to predict if an individual obese person will be one of those who will defeat the obesity, or will suffer the consequences.

There are changes that are likely to develop with age, like loss of muscle mass and loss of bone (osteopenia and osteoporosis). Whether weight loss is intentional or unintentional, there is a higher risk of bone loss (osteopenia and osteoporosis) and bone fractures, including hip fractures. Therefore, it cannot be emphasized enough that older patients (and, of course younger patients, too) who seek bariatric surgery should adhere to the dietary instructions, supplements and maintain a high level of activity, including exercise. They also should check their bone density, vitamin D and parathyroid hormone levels periodically.

Stay Healthy!

References:

Villareal DT, Apovian CM, Kushner RF, Klein S; American Society for Nutrition; NAASO, The Obesity Society. Obesity in older adults: technical review and position statement of the American Society for Nutrition and NAASO, The Obesity Society. Am J Clin Nutr. 2005 Nov;82(5):923-34. Review. [PMID: 16280421] (Full Text)

Wannamethee SG, Shaper AG, Lennon L.Reasons for intentional weight loss, unintentional weight loss, and mortality in older men. Arch Intern Med. 2005 May 9;165(9):1035-40.[ PMID: 15883243] (Abstract)

French SA, Folsom AR, Jeffery RW, Williamson DF.P rospective study of intentionality of weight loss and mortality in older women: the Iowa Women's Health Study. Am J Epidemiol. 1999 Mar 15;149(6):504-14. [PMID: 10084239] (Abstract)