Nitric oxide metabolites are associated with survival in older patients

To assess the efficacy of various vascular endocrinological substances, such as plasma nitric oxide metabolites (NOx), as surrogate markers of survival in older patients.

Prospective cohort, observational.

Nagoya University Hospital and related hospitals, Japan.

One hundred fifty patients aged 70 and older, recruited consecutively from the outpatient clinics of Nagoya University Hospital and related hospitals.

Serum biochemical analyses such as albumin and total cholesterol, various prognostic markers, such as tumor necrosis factor (TNF)-alpha, NOx, activities of daily living (ADLs), and instrumental ADLs (IADLs) were evaluated on enrollment. ADLs, IADLs, and comorbidities, especially depression and impaired cognition, were evaluated on enrollment. The main outcome was survival rate over 2.75 years.

Forty-nine patients died during the follow-up period. Mann-Whitney U-test showed that hemoglobin, total protein, serum albumin, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, high sensitive c-reactive protein, NOx, B-type natriuretic peptide, interleukin-6, and TNF-alpha levels; ADLs; cognitive impairment; and depressive status were significantly different for subjects who survived and those who died. Of the dependent variables in the Cox proportional hazards regression analyses, only ADLs, NOx, and albumin were significantly different. In the Kaplan-Meier analyses of mortality, the prognosis of patients in the third and fourth quartiles of NOx was significantly worse than that of patients in the first or second quartile. The prognosis of patients with impaired ADLs was worse than that of other patients for the overall period.

Lower levels of NOx may be associated with survival in older patients. It may be an effective marker, like ADLs, which is a well-known marker.