Vitamin D, cardiovascular disease, . . . and other storiesBMJ 2019; 366 doi: https://doi.org/10.1136/bmj.l4411 (Published 04 July 2019) Cite this as: BMJ 2019;366:l4411
Vitamin D supplements
Controversy over the value of vitamin D supplements continues. Wherever the balance of pros and cons lies, one benefit that can’t be expected is a reduction in risk of cardiovascular disease. A systematic review of 21 randomised trials that recruited more than 80 000 participants found nothing to suggest that long term vitamin D supplementation leads to any lowering of rates of stroke or myocardial infarction or to a reduction in all cause mortality (JAMA Cardiol doi:10.1001/jamacardio.2019.1870).
Neurofilament light chain
Neurofilament light chain (NfL) is a cytoplasmic protein highly expressed in large diameter myelinated axons. Levels in both blood and cerebrospinal fluid rise after axonal damage, which makes it a promising biomarker for brain damage after acute events such as cardiac arrest and in assessing prognosis and monitoring progression of chronic neurological diseases. A follow-up study of 600 patients with multiple sclerosis provides an example (Neurology doi:10.1212/WNL.0000000000007032). High serum levels of NfL at baseline were associated with an increased likelihood of relapse, worsening disability, and development of new lesions on magnetic resonance imaging.
Alcohol and breast cancer
Alcohol consumption is well established as a risk factor for breast cancer, but a small survey finds that this is not widely appreciated. In women attending either a breast clinic or for screening mammography, only about one in five was aware of the risk (BMJ Open doi:10.1136/bmjopen-2018-027371). The investigators wonder if screening mammography could be combined with a brief educational intervention. They point out that it has become routine practice to assess people for an inherited susceptibility to breast cancer but that there is no equivalent for people who have potentially modifiable lifestyle risk factors.
Reducing use of antimicrobials
Although almost everyone agrees that fewer antibiotics should be prescribed, there is little consensus on how this can be achieved. Many governments, including in the UK, have developed antimicrobial resistance action plans but few countries have implemented policies to reduce overuse (https://www.gov.uk/government/publications/uk-20-year-vision-for-antimicrobial-resistance). A systematic review examines several possible strategies including public awareness campaigns, better guidelines, and changing regulations around prescribing and reimbursement, but finds that only a small minority have been properly evaluated (PLoS Med doi:10.1371/journal.pmed.1002819). Of 69 studies of policy interventions to reduce antimicrobial use, only four were randomised controlled trials.
Maternal obesity during pregnancy raises the risk of type 2 diabetes in the offspring three or fourfold, according to a study from Scotland that linked 120 000 obstetric records to a national register of diabetes (Diabetolgica doi:10.1007/s00125-019-4891-4). Offspring of overweight mothers also had an increased risk of diabetes, although the risk was lower than that in the offspring of obese mothers. The underlying mechanisms might be genetic or involve mother and child sharing a similar environment, or be a consequence of antenatal metabolic programming. Unfortunately, no information about body mass index, physical activity, or other lifestyle variables in the offspring was available, so it’s hard to know which of these is most important.