LONDON -- Men who lose three centimeters or more of height (about 1.18 inches) as they age are at increased risk of death, compared with men who lose less than a centimeter, according to a longitudinal study here.
LONDON, Dec. 11 -- Excess shrinking as men age accelerates the risk of an earlier death, found investigators here.
A longitudinal study carried out here showed that men who lose three centimeters or more of height (about 1.18 inches) as they age are at an increased risk of death, compared to men who lose less than a centimeter, according to S. Goya Wannamethee, Ph.D., of the Royal Free and University College Medical School here.
The excess mortality was largely attributable to cardiovascular and respiratory conditions and other causes, but not to cancer, Dr. Wannamethee and colleagues reported in the Dec. 11 issue of Archives of Internal Medicine.
Height declines with age, but the impact of the lost stature on health hasn't been studied, the researchers said, so they evaluated data taken from the British Regional Heart Study, a prospective study of cardiovascular disease.
The study involved 7,735 men ages 40 to 59 years, who were selected from one general practice in each of 24 British communities from 1978 to 1980. Twenty years later -- when the men were between 60 and 79 -- 4,213 surviving members of the cohort underwent a follow-up exam.
For the main study, follow-up continued from the initial examination to 2005 for all-cause mortality and to 2006 for cardiovascular morbidity. But for this analysis, all-cause mortality was based on follow-up from re-screening during 1998 through 2000, with a mean follow-up of six years and cardiovascular morbidity was based on a mean follow-up of five years.
The mean height loss was 1.67 centimeters (about 0.66 inches), which was significantly correlated (at P<0.001) with initial age at the start of the study, the researchers found, and there were 760 deaths from all causes during the follow-up.
The researchers sorted the men into four height categories at the re-screening -- those who had lost less than a centimeter, those whose loss was from one to 1.9 centimeters, those who lost from two to 2.9 centimeters, and those who lost three or more.
The study found that, compared with men who lost less than one centimeter in height (about 0.39 inches), those who lost three centimeters or more had a 64% increase in all-cause mortality risk. The age-adjusted relative risk was 1.64, with a 95% confidence interval from 1.33 to 2.03.
Adjustment for other factors, including established cardiovascular risk factors, lung function, preexisting cardiovascular disease, albumin concentration, self-reported poor or fair health, and weight loss had only a modest impact on mortality risk, the researchers found. The adjusted relative risk was 1.45, with a 95% confidence interval from 1.15 to 1.82.
The study wasn't able to pin down exactly why the height loss is associated with an increased risk of death, Dr. Wannamethee and colleagues said, although osteoporosis increases the risk of death and may play a role.
However, osteoporosis usually causes a loss of six centimeters (2.36 inches) or more of height, and when the 283 men whose height loss was four or more centimeters were excluded from this analysis, the results were unchanged, the researchers said.
"The increased mortality risk was already seen in men with a height loss in the range of three centimeters to four centimeters and was not solely attributable to extreme height loss," the researchers concluded.
It's possible the some underlying mechanism is responsible both for height loss and for other health consequences that combine to give rise to the increased risk of death, the researchers said.
Initial heights in all four categories were equivalent, the researchers said, suggesting that selection bias was limited. The study was carried out in a population-based sample of men, so extending the results to women should be done cautiously.
The researchers reported no financial conflicts. The study was supported by the English health department.