Low Protein Intake Irrespective of Source is Associated with Higher Mortality Among Older Community-dwelling Men.
OBJECTIVES
Our aim was to determine the association between protein intake (overall and by source) and all-cause and cause-specific mortality among older men.


DESIGN
Prospective cohort study.


SETTING
5790 ambulatory community-dwelling older men from multicenter Osteoporotic Fractures in Men (MrOS) study.


MEASUREMENTS
Total energy and protein intake, and protein intake by source (dairy, non-dairy animal, plant) were assessed using a 69-item food frequency questionnaire. We included up to 10-year follow-up with adjudicated cardiovascular, cancer and other mortality outcomes. We used time-to-event analysis with protein exposures, mortality outcome, and adjusted for possible confounders including age, center, education, race, smoking, alcohol use, physical activity, weight, total energy intake (TEI), and comorbidities. Hazard ratios were expressed per each unit=2.9% TEI decrement for all protein intake variables.


RESULTS
The mean (SD) baseline age of 5790 men was 73.6 (5.8) y. There were 1611 deaths and 211 drop-outs prior to 10 years, and 3868 men who were alive at the 10-year follow-up. The mean (SD) total protein intake was 64.7 (25.8) g/d, while the mean (SD) intake expressed as percent of total energy intake (%TEI) was 16.1 (2.9) %TEI. Lower protein intake was associated with an increased risk of death, with unadjusted HR=1.11 (95% CI: 1.06, 1.17) and adjusted HR=1.09 (95% CI: 1.04, 1.14) and the associations for protein intake by source were similar. The adjusted HR for cancer mortality was HR=1.13 (95% CI: 1.03, 1.25) while the association for CVD mortality was HR=1.08 (95% CI: 0.99, 1.18).


CONCLUSIONS
Low protein intake, irrespective of source, was associated with a modest increase in risk of all-cause and cause-specific mortality among older men. Special consideration should be given to level of protein intake among older adults.
['Langsetmo|L|L|', 'Harrison|S|S|', 'Jonnalagadda|S|S|', 'Pereira|S L|SL|', 'Shikany|J M|JM|', 'Farsijani|S|S|', 'Lane|N E|NE|', 'Cauley|J A|JA|', 'Stone|K|K|', 'Cawthon|P M|PM|']
D000368:Aged D018753:Diet, Protein-Restricted D002149:Energy Intake D006801:Humans D057187:Independent Living D008297:Male D009026:Mortality D011446:Prospective Studies D012307:Risk Factors
Protein intake cause-specific mortality older men all-cause mortality