Suicide rate lower for obese men
Men who are overweight or obese are less likely to commit suicide than other men, says a recent analysis using the Health Professionals Follow-up Study. This supports earlier research findings. The new study looked at data for 46,755 men over a period of 17 years, during which time 131 men died from suicide (from1986 until 2002). Suicide risk was lowered by 11 percent for each 1.0 unit increase of BMI.
The study also found that mental health-related quality of life improved as BMI increased. (Archives of Inter Med, March 12, 2007; Medline Plus NIH, March 13, 2007)
Alcohol increases waist-to-hip ratio
In a representative sample of French men and women, the more alcohol they drank, the larger their waist-to-hip ratio and waist girth. This was independent of body mass index, age, physical activity, socioeconomic level, and smoking.
Total alcohol consumption was what mattered, not whether it was wine, beer, or spirits. There was no protective effect of wine against abdominal fat disposition. This disputes the common belief that drinking beer promotes abdominal fat distribution whereas wine does not. (The authors note that French people drink more wine than any other alcoholic beverage, at 67 percent of total alcohol intake.) The study suggests a specific effect of alcohol on abdominal fat deposition, the researchers said. (Dallongeville J, Marecaux N, Ducimetiere P, et al. Influence of alcohol consumption and various beverages on waist girth and waist-to-hip ratio in French men and women. Int J Obesity 1998; 1178-1183.)
BMI often mislabels risk
One-quarter of children labeled as "at risk" of overweight (body mass index over the 85th percentile) turned out to have normal body fat, in a USDA study of 979 children age 3 to 18. There were also errors in under-identifying kids with high body fat: one in six with a normal range BMI had an unhealthy level of body fat. Body fat ranged from 10 to 40 percent. Mislabeling of this many children is a major concern when only BMI is used in predicting risk, rather than considering such factors as age, sex, maturity, ethnicity, and physical activity. However, the authors note, BMI can provide a general profile in a population. . (Federal Update: BMI poor indicator of body fat in individual kids. J AM Diet Assoc 2000;100:628)
Diabetes treatment and obesity: a dilemma
Obesity is a major risk factor for the development of type 2 diabetes, and weight loss is often recommended. Yet conventional treatments with insulin and sulphonylureas often lead to weight gain, points out Gareth Williams, MD, of the University Hospital Aintree, Liverpool, UK. Thus, he sees managing a patient with type 2 diabetes and obesity as a "conflict of interests." Current estimates are that the incidence of type 2 diabetes will increase by 50 percent over the next 7 or 8 years, bringing the total number of people worldwide with the disease to 150 million. This is a dilemma that needs to be recognized and dealt with, says Williams. ( Williams G. Obesity and type 2 diabetes: a conflict of interests? Int J Obes Relat Metab Disord 1999; 23 Suppl 7:S2-S4.)
Obesity is protective in hospital survival
Larger patients survived better than thinner patients in a comprehensive study of adults with acute lung injury who were being treated in intensive care units. The study, conducted by Ohio State University researchers between 1995 and 2001, included 1,488 mechanically ventilated adults with acute lung injury treated in 106 intensive care units at 84 hospitals in the Project IMPACT database.
Both before and after risk-adjustment, the risk of hospital death was highest in a continuous variable for the underweight group, lower for the normal weight group and at its lowest point for the obese and severely obese groups (BMI 35 to 40). After this point risk increased somewhat but remained well below that of the underweight group.
Further, their functional status at hospital discharge was more often impaired in underweight survivors, while obese patients were significantly more likely to return to their previous functional status. (Over half the patients had a body mass index of 25 or above.)
The authors say their findings are consistent with previous reports on the protective effect of obesity for a number of conditions including hospitalized patients, patients with pneumonia, those needing hemodialysis, those with HIV, and those who have undergone heart transplants. Studies suggest increased mortality in low-BMI population subgroups, they report.
“Despite our large sample size, we did not identify increased mortality in the overweight, obese, or severely obese patient groups. In fact, the overweight group showed decreased mortality, and both the overweight and obese groups showed improved functional status at hospital discharge.… It may be that other factors such as nutritional reserve play a beneficial compensatory role in these patients,” say the Ohio authors.
Their findings show no difference by age when patients under and over 65 were analyzed separately, although they note that some writers suggest that obesity may confer a greater risk for younger hospitalized patients. (O'Brien JM, Phillips GD, et al. BMI independently associated with hospital morality in mechanically ventilated adults with acute lung injury. Critical Care Med 2006;34:738-744.)
Breast cancer undertreated in large patients
Obese breast cancer patients are twice as likely to get lower than optimal doses of chemotherapy, say researchers at the University of Rochester Medical Center in New York. In checking the records of 764 women treated for breast cancer between 2002 and 2005 they found that 21 percent of obese women received less than 85 percent of the standard dose for their weight, compared with just 10 percent of lean women who were undertreated. The women were treated at 115 randomly selected private oncology practices around the country.
A dose lower than optimal can affect how the breast cancer responds as well as its risk of recurrence, the researchers said. “Sometimes we’re not curing people because they are not getting the full doses that should be standard.”
While some doctors may worry about giving the high dose of chemotherapy calculated according to an obese woman’s height and weight, they report that research has shown obese women given this correct dosage don’t experience any extra problems. (Reuters Health: Washington. 1/19/07; J of Clinical Oncology 1/18/2007.)
Obesity risks in pregnancy
Pregnancy is a high-risk time for women to gain excess weight that may be retained after childbirth. A higher weight gain in pregnancy may also contribute to having high birth-weight babies, and perhaps to childhood obesity.
A recent Temple University study analyzed data on 7,660 women from the New Jersey Pregnancy Risk Assessment Monitoring System data to assess these weight-related issues. Eighteen percent of the mothers were obese, 13 percent overweight, 53 percent “normal weight” and 16 percent underweight. About half of the women considered overweight or obese gained more weight than recommended during pregnancy. These two groups were more likely to have a Caesarean section and less likely to breastfeed. Their babies also had an increased chance of high birth weight.
The researchers suggest that mothers be counseled to follow the Institute of Medicine's recommendations for healthy pregnancy weight gain based on their pre-pregnancy BMI. (Researchers Call for More Aggressive Weight Control Before, During Pregnancy to Reduce Maternal and Childhood Obesity Risk, United Press International, 7/13/07; Temple University release, 7/14/2007; Jain et al., American Journal of Perinatology, May 2007.)
Fertility events link to women's weight gain
Three high-risk times for excess weight gain in a woman's life are all related to fertility events, according to several studies presented at the annual meeting of the North American Association for the Study of Obesity in Long Beach, CA. The key times are when menstruation begins, with pregnancy, and with menopause.
Studies at Tufts University, Boston, show that early menarche may be an intermediate on the pathway to later obesity and also contribute independently to increased risk of later obesity. The researchers suggest that early menarche, if established as a critical period, could be targeted for obesity prevention. Weight retention after pregnancy, long established as a risk factor for obesity, is shown to be a greater risk for African-American than Caucasian women. The Women's Healthy Lifestyle Project, a 5-year randomized clinical trial of 535 initially premenopausal women funded by the National Institutes of Health, shows that postmenopausal women have higher levels of body fat and central adiposity than other women the same age. (Women have high-risk periods for weight gain. MedscapeWire 11/6/2000)
American Indian heart disease not linked to obesity
More than 75 percent of middle-aged and older Native Americans are overweight or obese (body mass index [BMI] of 25 or over) in recent research on risk factors for heart disease in the Strong Hearty Study of Arizona, Oklahoma, and North and South Dakota. BMI is higher in women than men, in younger than older people, and in those with diabetes versus nondiabetic persons. The majority have central obesity, and percent body fat is extremely high.
Yet, paradoxically, increasing obesity had only a modest influence on risk factors for coronary heart disease, and waist circumference had no special effect over BMI on these risk factors. Except for insulin, the changes in risk factors with increasing obesity were not large. Thus, the relations among obesity, body fat distribution, and heart disease risk may differ for American indians. The authors cite a large population study of Pima Indians that shows little relation between obesity and death rates.
The study included 4,549 men and women age 45 to 74 in the three areas. For both men and women, all measures of weight, waist, BMI, and percent body fat were lower in the Dakotas and higher in Arizona, where the authors said lifestyles may be more sedentary. (Gray R, Fabsitz R, Cowan L, et al. Relation of generalized and central obesity to cardiovascular risk factors and CHD in American Indians: the Strong Heart Study. Int J Obes 2000;24:849-860)
Viral connection to obesity
The role of a virus infection in the development of obesity must be considered, say University of Wisconsin researchers. In four separate experiments, they inoculated chickens and mice with a human adenovirus (AD-36) and found that visceral fat, total body fat, and/or body weight were significantly greater, compared with control groups. Increased adiposity could be seen as soon as 3 weeks and persisted for 13 and 22 weeks when the studies ended. Previously, it was not thought that these viruses could infect across species.
The Wisconsin researchers demonstrated earlier that obesity can be induced by an avian adenovirus in four animal models. They cite research that found that canine distemper virus can produce obesity in mice and that it was believed to be related to hypothalamic damage. They also cite reports that some obese humans have antibodies to avian adenovirus. (Healthy Weight Journal 2000:14:6;83 / Dhurandhar NV, Israel BA, Kolesar JM, et al. Increased adiposity in animals due to a human virus. Int J Obes 2000;24:989-996)
Low weight predicts fractures for older women
Thin elderly women suffer more fractures than larger women, according to Minnesota researchers working with the Study of Osteoporotic Fractures. In a 6.4-year follow-up of 8,059 women age 65 and older, women in the lowest quartile of weight had 2 to 2.4 times the risk of hip, pelvic, and rib fractures as women in the highest quartile. They conclude that in recommendations for screening and treatment decisions, low weight should be considered a risk factor for these fractures. Weight did not predict fractures of the humerus, elbow, wrist, ankle, or foot. (Low body weight increases risk of some fractures in elderly women. Reuters Medical News, Westport 7/18/00. Ann Inten Med 2000;133:123-127)
Death rate lowest at BMI of 34
Disputing guidelines that say health risks begin at a body mass index of 25, the Panel Study of Income Dynamics, which looked at women age 50 and over, found the point of lowest risk to be much higher than this. The four-year study of 1,355 women found a broad U-shaped relationship between BMI and mortality, suggesting that a broad range of weight is well tolerated by older women. Mortality risk was lowest among both smoking and nonsmoking women at a BMI of around 34. High risk at lower weights did not appear to be explained by smoking, as the effect remained when controlled for smoking. (Healthy Weight Journal 1999:13:5;66 / Fontaine KR, Heo M, Cheskin LJ, Allison DB. Body mass index, smoking, and mortality among older American women. J Women's Health 98;7:1257-1261.)