eMJA: In Other Journals, 18 April 2005

A short-term low-carbohydrate diet can lead to beneficial effects beyond weight loss in patients with obesity and type 2 diabetes, say US researchers. Boden and colleagues measured the effect of a strict 20 g carbohydrate per day diet over a 2-week period in 10 obese patients with type 2 diabetes. They found that the patients' energy intake spontaneously dropped by a third, with an average weight loss of 1.65 kg over the fortnight. However, the patients also demonstrated improved 24-hour blood glucose levels and insulin sensitivity; reduced haemoglobin A1c results; as well as decreased plasma triglyceride and cholesterol levels.

Obesity v longevity

The youth of today may live shorter and less healthy lives than their parents unless interventions to reduce obesity are developed, say US experts. In a special report, Olshansky and colleagues warned that the current obesity epidemic, together with future threats from infectious diseases, could lead to life expectancy at birth levelling off or even declining within the first half of this century. They say the negative effects of obesity would override the gains made by eliminating other major fatal diseases, such as cancer.

N Engl J Med 2005; 352: 1138-1145

Smoking babies?

Maternal smoking may cause genotoxic damage to the fetus, according to Spanish research.1,2 de la Chica and colleagues cultured amniocytes, obtained at routine amniocentesis for prenatal diagnosis, from 25 women who had smoked 10 or more cigarettes daily for 10 or more years (including during their pregnancy) and 25 controls. Amniocytes cultured from the women who smoked had a more than threefold increase in frequency of chromosomal aberrations, especially deletions and translocations. Chromosomal instability has previously been associated with an increase in the risk of cancer, especially childhood malignancy.

1. JAMA 2005; 293: 1212-1222
2. JAMA 2005; 293: 1264-1265

Drug withdrawals

Did a faster, less stringent drug-approvals process in Canada in the 1990s lead, in that same decade, to a greater number of drugs being withdrawn from that market because of safety concerns, a Canadian commentator has asked. Undeterred by a lack of basic information available from Health Canada, Professor Lexchin hand-searched various data sources to determine that between January 1963 and May 2004, at least 41 over-the-counter and prescription products had been withdrawn from the Canadian market for safety reasons — 10, 6 and 7 in the first three decades respectively, and 16 since 1993. Apart from a speedier approvals process, Lexchin said more sophisticated methods for recognising serious safety issues and having more information available from local and overseas sources may also have contributed to the increase in drug withdrawals since 1993. His over-arching concern was that, currently, Health Canada seemed to have an inadequate system for monitoring the safety of marketed drugs.

CMAJ 2005; 172: 765-767

Heterosexual HIV

Heterosexual intercourse was linked to HIV infection in 21 115 people in England, Wales and Northern Ireland diagnosed between 1985 and 2003, according to authors from the UK Health Protection Agency Centre for Infections. Although only 9% of cases were infected in the UK (most having been infected in Africa, Latin America and the Caribbean), the number of HIV infections acquired through heterosexual intercourse in the UK has risen in recent years, from 144 in 1999 to 315 in 2003. The authors are concerned that as the number of heterosexuals living with HIV (diagnosed and undiagnosed) in the UK grows, the likelihood of heterosexual transmission within the country will increase, particularly among ethnic minorities.

www.bmj.com

Mothers of advanced age

Australian researchers have good news for expectant women of very advanced maternal age — that is, 45 years or older. They studied the outcomes of pregnancies progressing beyond 20 weeks' gestation in 76 women of advanced maternal age seen over a 10-year period at Brisbane’s two major tertiary obstetric units. About four in five of the pregnancies in the older women had been conceived naturally. Although the rate of caesarean section was higher in older women than younger women aged 20 to 29 years (49% v 23%), the maternal and neonatal outcomes were generally as good in the older group. The researchers said their study was reassuring for older women who are healthy and who have a chromosomally normal fetus.

Aust N Z J Obstet Gynaecol 2005; 45: 12-16

Dr Ann Gregory, MJA

The Medical Journal of Australia eMJA