Sleeping pills taken by an obese person magnify the death risk, nearly doubling its rate even among those prescribed 18 or fewer pills in a year.
"The associations between sleeping pills and increased mortality were present, and relatively stronger, even in people aged 18 to 54," said Robert Langer, family physician and epidemiologist with the Jackson Hole Centre for Preventive Medicine.
Among obese patients, the use of sleeping pills was linked to about one extra death per year for every 100 people who were prescribed the medication, Langer said, the journal BMJ Open reports.
"Obese patients appear particularly vulnerable, perhaps through interaction with sleep apnea," said study co-author Daniel Kripke, psychiatrist with Scripps Clinic's Viterbi Family Sleep Centre in San Diego.
He noted that sleeping pills were previously tied with more and longer pauses in breathing in people with sleep apnea. Additionally, men who took sleeping pills were about twice as likely to die as women who received the medication, after accounting for other factors, Kripke said.
These findings are based on the Scripps Clinic-led study of almost 40,000 patients, according to a Scripps Clinic statement.
The research was the first to show that eight of the most commonly used hypnotic (sleep inducing) drugs were linked with increased hazards of mortality and cancer, including the popularly prescribed medications zolpidem (known by the brand name Ambien) and temazepam (also known as Restoril), Kripke said.
These findings were presented at the annual American Heart Association's Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2012 Scientific Sessions in San Diego.