Deaths from Acute Respiratory Infections are Linked to High Fasting Blood Glucose and Decreased Levels of Low-Density Lipoprotein/Small Dense Low-Density Lipoprotein.

Abstract

Purpose: Winter poses a significant threat to acute respiratory infections (ARIs), often leading to severe outcomes including mortality. This study investigated the effect of glucose and lipid metabolism on mortality rates among individuals with ARIs.

Patients and methods: We collected clinical data including indicators related to glucose and lipid metabolism, liver and kidney function, complete blood count, coagulation function, and other parameters from 1675 hospitalized patients with ARIs who were consecutively admitted during the winter season. The clinical characteristics and influencing factors associated with mortality in these patients were analyzed.

Results: Risk factors contributing to mortality in patients with ARIs include fasting blood glucose (FBG), low-density lipoprotein (LDL), apolipoprotein E (ApoE), small dense LDL (sdLDL), D-dimer, lymphocyte count, blood urea nitrogen, and a history of diabetes. Notably, when FBG above 7.8 mmol/L, mortality followed a parabolic association with HbA1c-lowest at extremes (<5.7% or ≥8.5%) but markedly higher in the mid-range (5.7-8.4%). Among patients with diabetes, those who succumbed to the infection exhibited higher FBG levels but lower glycated hemoglobin (HbA1c) levels than those who recovered. Moreover, low levels of LDL/sdLDL and high levels of ApoE were inversely and positively linked, respectively, to mortality rates.

Conclusion: In patients with ARIs, FBG level, rather than HbA1c level, is a risk factor for mortality. Moreover, low LDL/sdLDL levels and high ApoE levels are associated with increased mortality. The retrospective design and lack of long-term follow-up may limit the findings, highlighting the need for prospective validation.