Exercise linked to reduced risk of several cancers

Physical activity has been associated with lower risk of heart disease and all cause mortality, but its association with risk of cancer is not well understood.

Moore et al research published in JAMA Internal Medicine, suggests that exercise is a powerful cancer-preventive and found that physical activity drove down the rates of a broad array of cancers even among smokers, former smokers, the overweight and obese.

Researchers collected data from 12 prospective studies from the United States and Europe and analyzed associations between self-reported physical activities with the incidence of 26 types of cancer in the study period, which lasted 11 years between 1987 and 2004.

A total of 1.44 million participants (median [range] age, 59 [19-98] years; 57% female) and 186 932 cancers were included. High versus low levels of physical activity were associated with lower risk of 13 cancers: esophageal adenocarcinoma, liver, lung, kidney, gastric, endometrial, myeloid leukemia, myeloma, colon, head and neck, rectal, bladder, and breast. The data indicated that a higher level of activity was tied to a 7 percent lower risk of developing any type of cancer. Individuals who were very active had a 20% lower risk of cancers of the esophagus, lung, kidney, stomach, endometrium compared with people who were less active.  The reduction was slightly lower for colon, bladder, and breast cancers.

Body mass index adjustment modestly attenuated associations for several cancers, but 10 of 13 inverse associations remained statistically significant after this adjustment. Leisure-time physical activity was associated with higher risks of malignant melanoma and prostate cancer.  Associations were generally similar between overweight/obese and normal-weight individuals. Smoking status modified the association for lung cancer but not other smoking-related cancers.

Health care professionals should emphasize that physical activity was associated with lower risks of many cancer types and most of these associations were evident regardless of body size or smoking history.

Insufficient sleep common among US adults

The Centers for Disease Control and Prevention (CDC) released a report revealing that about one-third of adults in the US appear to be getting insufficient sleep. 

After surveying 444,306 US adults in 2014, CDC found that while two-thirds of white people nationally got enough sleep, only about half of blacks, Native Hawaiians and Pacific Islanders did. 

Among the respondents, 11.8% reported a sleep duration of 5 hours or less, 23.0% reported 6 hours, 29.5% reported 7 hours, 27.7% reported 8 hours, 4.4% reported 9 hours, and 3.6% reported 10 hours or more.

Overall, 65.2% reported the recommended healthy sleep duration of 7 hours.  The age-specific prevalence of sleeping ≥7 hours was highest among respondents aged ≥65 years (73.7%).  The prevalence of healthy sleep duration was highest among respondents with a college degree or higher (71.5%). The prevalence was higher among married respondents (67.4%) compared with those who were divorced, widowed, or separated (55.7%), or never married (62.3%).

Healthy sleep duration ranged from 71.6% in South Dakota, which has the largest proportion of residents who get at least seven hours of sleep each night, to 56.1% of Hawaii that has the lowest proportion. A lower prevalence of healthy sleep duration was observed in the southeastern United States and in states along the Appalachian Mountains.

       

CDC’s report states that sleeping less than seven hours per night is associated with increased risk for obesity, diabetes, high blood pressure, coronary heart disease, stroke, frequent mental distress, and all-cause mortality.

As more than one third of U.S. respondents, or approximately 84 million U.S adults reported sleeping less than 7 hours in a 24-hour period.  The need for public awareness and public education about sleep health is urgently needed.  In addition worksite shift policies that ensure healthy sleep duration for shift workers, particularly medical professionals, emergency response personnel, and transportation industry personnel should be implemented.

Exercise may reduce injuries from falls in older men

Gill et al in a BMJ article reported findings of potential beneficial effect(s) exercise may have in reducing falls among the elderly.   The authors derived their data from the Lifestyle Interventions and Independence for Elders (LIFE) trial.  The research included 1635 sedentary men and women aged 70-89 years with functional limitations, as defined with a short physical performance battery score (SPPB) equal to or less than 9, but who were able to walk 400 meters. 

The SPPB consists of a battery of tests that combines results from gait speed, standing from a chair and balance as was described by Guralnik etal.  Scores range from 0 (worst performance) to 12 (best performance). Thus SPPB has been used as a predictive tool for assessing possible disability and/or for monitoring of function in older people. 

The participants in the LIFE study were randomly assigned to a structured, moderate intensity physical activity program (n=818) conducted in a center and at home that included aerobic, strength, flexibility, and balance training activities, or to a health education program (n=817) consisting of workshops on topics relevant to older people and upper extremity stretching.

The study found that the rate of falling did not differ significantly between those who received health education versus those who were asked to increase their physical activity.  Over two years, 61.2 percent reported at least one fall in the first group, while 60 percent did in the second.  Serious fall injuries, defined as a fall that resulted in a fracture and/or injury that led to a hospital admission, was experienced by 84 (10.3%) in the health education group and 75 (9.2%) of the participants in the physical activity group.

The investigators found the male participants in the exercise group boosted their physical activity, and also had greater improvements in gait, balance and muscle strength comparing to those in the health education group.  This resulted in a 38 percent lower risk of serious fall injuries, a 53 percent lower risk of fall-related fractures, and a 59 percent lower rate of fall injuries requiring hospitalization for the men in the workout group. However, the exercise program did not appear to reduce women’s risk of serious injuries.

Approximately 30 per cent of the elderly fall each year.  In 2010, 2.3 million non-fatal fall injuries were treated in U.S. emergency departments, and more than 662,000 of these patients were admitted to the hospital.  The results of this study are suggestive that even modest interventions in physical activity as those practiced by the participants in this study may result in a reduction in the number of falls and in the associated morbidity and mortality from the resulting injuries.  The sense of security due to enhanced sense of balance may also result in better-quality of life among the elderly.

Decades long decline in Dementia

A study by Satizabal et al published in the NEJM found that dementia rates fell steadily over the past three decades, likely due to declining rates of heart disease.

The study analyzed data collected since 1975 from the Framingham Heart Study and included 5205 persons 60 years of age or older.  The authors compared interactions between epoch and age, sex, apolipoprotein E ε4 status, educational level, as well as the effects of vascular risk factors such as cardiovascular disease on the prevalence of dementia.

The 5-year age-and sex-adjusted cumulative hazard rates for dementia were 3.6 per 100 persons during the first epoch (late 1970s and early 1980s), 2.8 per 100 persons during the second epoch (late 1980s and early 1990s), 2.2 per 100 persons during the third epoch (late 1990s and early 2000s), and 2.0 per 100 persons during the fourth epoch (late 2000s and early 2010s). Relative to the incidence during the first epoch, the incidence declined by 22%, 38%, and 44% during the second, third, and fourth epochs, respectively. This risk reduction was observed only among persons who had at least a high school diploma. The prevalence of most vascular risk factors (except obesity and diabetes) and the risk of dementia associated with stroke, atrial fibrillation, or heart failure have decreased over time, but none of these trends completely explain the decrease in the incidence of the disease.

The authors concluded that the incidence of dementia has declined over the course of three decades.

N Engl J Med 2016; 374:523-532