Fact or old wives’ tale? A change in the weather can make bones and joints ache. A new study has an answer: tale. Researchers looked at medical records of 11,673,392 Medicare outpatient visits. Matching the dates of the visits to local weather reports, they found that 2,095,761 of them occurred on rainy days. Using probability estimates, they predicted how many of those visits were for a condition related to joint or back pain. After controlling for other factors, they found that more visits for bone and joint pain happened on dry days than wet ones — 6.39 percent for dry and 6.35 percent for wet days, a difference so small as to have no clinical significance.

High glucose tied to heart defects in babies

Women with high glucose readings early in pregnancy are at increased risk of having a baby with heart defects, even if they do not have full-blown diabetes, a new study found. Researchers studied data on 19,107 mothers, members of two large health care systems, of whom 811 gave birth to babies with congenital heart disease. The data included blood glucose measurements done between four weeks before conception and the 14th week of gestation. The study, in the Journal of Pediatrics, found that for each 10-milligrams-per-deciliter rise in plasma glucose, there was an 8 percent increase in the risk for giving birth to a baby with heart defects, even after adjusting for other factors.

Vigorous exercise could lead to vision loss

A new study suggests that vigorous physical activity may increase the risk for vision loss. Using questionnaires, Korean researchers evaluated physical activity among 211,960 men and women ages 45 to 79 in 2002 and 2003. Then they tracked diagnoses of age-related macular degeneration, from 2009 to 2013. Researchers found that exercising vigorously five or more days a week was associated with a 54 percent increased risk of macular degeneration in men. They did not find the association in women.