Review of the Recent Medical Literature

OC Use Linked to Breast Cancer in Young Women
One debate about the risks associated with oral contraceptives (OCs) may have finally been settled. A new meta-analysis of 34 published case-control studies shows that OC use significantly increases risk for breast cancer in childbearing-aged women. The risk increases by 29% in parous women and by 24% in nulliparous women. Among parous women, the risk is greater when OC use begins before the first full-term pregnancy than after it. The association between OC use and breast cancer risk is greatest in parous women who use OCs for ≥4 years before the first full-term pregnancy. Duration of OC use did not appear to affect risk in nulliparous women.

Carpal Tunnel May Signal Prediabetes
Carpal tunnel syndrome predates the diagnosis of type 2 diabetes by up to 10 years. The finding is based on a study of the medical records obtained from 114 family practices that included 2647 patients diagnosed with type 2 diabetes and 5294 matched controls. Investigators reviewed medical records for up to 10 years before diabetes was diagnosed. The incidence of carpal tunnel syndrome was 425.1 per 100,000 person-years in the prediabetes group compared with 260 per 100,000 person-years in the control group. After adjusting for known risk factors, the risk of type 2 diabetes was 36% higher in patients with carpal tunnel than in the controls.

Lack of Fingerprints from Protein Deficit
Naegeli syndrome and dermatopathia pigmentosa reticularis, 2 rare congenital diseases in which afflicted patients have no fingerprints, have been linked to a defect in the keratin 14 protein that induces the body to mark cells in the outer layers of the skin for death. As a result, patients with these disorders do not have finger lines and cannot perspire normally. They also suffer from thickening of the palms and soles. Researchers are now focusing on understanding the connection between the unusual features of these diseases and enhanced programmed cell death.

Petrochemical Exposure May Contribute to Leukemia
Residential petrochemical exposure is associated with an increased risk of leukemia in young adults. The finding emerged from a population-based study of 171 persons aged 29 years and younger with leukemia and 410 matched controls. Individual petrochemical exposure was determined using a geographic information system tool based on participants' mobility, length of stay at each residence, distance to petrochemical plants, prevailing wind direction, and other factors. As the log-transformed petrochemical exposure opportunity score increased by 1 unit, the risk of leukemia increased by 54% among those aged 20 to 29 years. However, no relationship was found between petrochemical exposure and leukemia risk in those aged ≤19 years.

Topical NSAIDs Effective in Knee OA
A systematic review of controlled clinical trials has concluded that topical nonsteroidal antiinflammatory drugs (NSAIDs) can provide effective pain relief for patients with knee osteoarthritis (OA). Investigators identified 172 literature citations, 4 of which fulfilled the specified study criteria: trial duration of ≥4 weeks and comparison of any topical NSAID with placebo or vehicle in patients with primary knee OA. Overall, the pooled effect of treatment with topical NSAIDs measured at 4 weeks or beyond was superior to placebo or vehicle for pain relief (mean effect size, ±0.28). The relative efficacies of specific topical NSAID preparations were not evaluated.

Migraines and Sexual Drive
Persons with migraines report higher levels of sexual desire than those with other types of headache, based on data from a study of 23 patients with migraine and 36 patients with tension-type headache who completed the Brief Headache Diagnostic Interview and Sexual Desire Inventory (SDI). Compared with the tension-type headache patients, those with migraine headache had higher SDI scores and higher self-rated levels of sexual desire. The symptom "headache aggravated by routine physical activity" predicted a high SDI score. These data suggest that similar serotonergic phenomena may be at the root of both migraines and sexual desire.