Lung function and blood markers of nutritional status in non-COPD aging men with smoking history: A cross-sectional study

Nobuyoshi Shiozawa¹, Kanae Hayashimoto², Etsuji Suzuki⁵, Hiroshi Kikuchi³, Shingo Takata³, Kozo Ashida³, Masutaka Watanabe⁴, Yasuhiro Hosaki⁶, Fumihiro Mitsunobu<sup>1,3

1</sup>Department of Geriatric Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Misasa, Tottori, Japan; ²Nutrition Support Service and Divisions of ³Internal Medicine and ⁴Rehabilitation, Okayama University Hospital Misasa Medical Center, Misasa, Tottori, Japan; ⁵Department of Epidemiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan; ⁶Division of Internal Medicine, Hiroshima Teishin Hospital, Hiroshima, Japan

Purpose: Cigarette smoking and advanced age are well known as risk factors for chronic obstructive pulmonary disease (COPD), and nutritional abnormalities are important in patients with COPD. However, little is known about the nutritional status in non-COPD aging men with smoking history. We therefore investigated whether reduced lung function is associated with lower blood markers of nutritional status in those men.

Subjects and methods: This association was examined in a cross-sectional study of 65 Japanese male current or former smokers aged 50 to 80 years: 48 without COPD (non-COPD group), divided into tertiles according to forced expiratory volume in one second as percent of forced vital capacity (FEV₁/FVC), and 17 with COPD (COPD group).

Results: After adjustment for potential confounders, lower FEV₁/FVC was significantly associated with lower red blood cell count (RBCc), hemoglobin, and total protein (TP); not with total energy intake. The difference in adjusted RBCc and TP among the non-COPD group tertiles was greater than that between the bottom tertile in the non-COPD group and the COPD group.

Conclusion: In non-COPD aging men with smoking history, trends toward reduced nutritional status and anemia may independently emerge in blood components along with decreased lung function even before COPD onset.

Keywords: anemia, chronic obstructive pulmonary disease, lung function, nutritional assessment, nutritional status, smoking