VITAMIN d LEVEL TIED TO FIBROIDS
Inadequate levels of vitamin D may increase the risk for uterine fibroids, a new study reports. Vitamin D has been associated with reduced risk for various diseases, but this is the first to examine the connection to fibroids, benign tumors of the uterus that can cause pain and bleeding.
Researchers randomly selected 620 black and 410 white women, ages 35 to 49, and determined their vitamin D levels with blood tests and their health status with questionnaires. Their analysis appears in the May issue of Epidemiology.
About two-thirds of the women had fibroid tumors. In the entire group, only 10 percent of the black women and 50 percent of white women had vitamin D levels above 20 nanograms per milliliter, generally considered an adequate level.
After adjusting for age, physical activity, sun exposure and other variables, they found that having a vitamin D level above 20 decreased the risk for fibroids by 32 percent, and that each increase of 10 nanograms per milliliter in vitamin D was associated with a 20 percent lower risk of having a fibroid tumor.
HEART RATE AND LIFE SPAN
A study published in Heart suggests that a higher resting heart rate is an independent predictor of mortality — even in healthy people in good physical condition. Danish researchers gave physical exams to 5,249 healthy middle-aged and elderly men beginning in 1971. In 1985 and 1986, they tracked the 3,354 survivors. Of these, 2,798 had sufficient data on heart rate and oxygen consumption for the analysis. Researchers followed them through 2011.
After controlling for physical fitness and many other factors, they found that the higher the resting heart rate, the greater the risk for death. Compared with men with rates of 50 beats a minute or less, those at 71 to 80 beats had a 51 percent greater risk. At 81 to 90 beats, the rate of death was doubled, and over 90 it was tripled.
"If you have two healthy people," said the lead author, Dr. Magnus Thorsten Jensen, a researcher at Copenhagen University Hospital Gentofte, "exactly the same in physical fitness, age, blood pressure and so on, the person with the highest resting heart rate is more likely to have a shorter life span."
THE TOLL OF STRESS
High levels of cortisol — the so-called stress hormone — have been associated with heart disease in some studies, but not in others. This may be because measuring cortisol in blood or saliva at one point in time may pick up acute stress, but it fails to account for long-term stress.
Now Dutch researchers have assessed cortisol levels over several months by analyzing scalp hair samples. Their results appeared online in the Journal of Clinical Endocrinology and Metabolism.
The researchers measured the cortisol content in hair samples corresponding to roughly three months of growth from 283 older men and women, average age 75. Compared with those in the lowest quarter for cortisol, those in the highest quarter had about three times the risk for cardiovascular disease and diabetes. There was no association between cortisol levels and the risk for lung disease, cancer or osteoporosis.
The researchers had no data on blood pressure or lipid status, which may have affected the results. But "the increased risk," said Dr. Elisabeth van Rossum of the Erasmus Medical Center in Rotterdam, is comparable to traditional risk factors — hypertension and abdominal obesity.
It's all about a mother's EMBRACE
New mothers quickly learn that babies quiet down when carried and rocked. Now researchers say that this calming response is actually a coordinated set of reactions, involving the nervous, motor and cardiac systems. Dr. Kumi O. Kuroda, a neurobiologist at the Riken Brain Science Institute in Japan, led a team that used electrocardiogram measurements to monitor the heart rates of babies and mice after they were picked up and carried. Their heart rates slowed almost immediately.
"It's very difficult for adults to relax so quickly," said Kuroda, whose study appears in the journal Current Biology. "I think it's specific to infant physiology."
In the case of mouse pups, it took only one second for the heart rate to drop. In human babies, it took about three seconds. The researchers worked with babies under 6 months; the response was stronger in those 3 months and younger.
Both babies and mouse pups also stopped moving after they were carried, and the mice stopped emitting ultrasonic cries.