Stress and Allostatic Load in Patients With Primary Open Angle Glaucoma

Precis: This study evaluated the allostatic load (AL) in primary open angle glaucoma (POAG) patients and reported that the AL score was significantly higher in glaucoma patients compared with age-matched controls. Purpose: To evaluate the AL in patients with POAG. Methods: This case-control study comprised 50 POAG (glaucoma patients) and 50 age-matched controls without glaucoma (controls). AL was estimated based on 13 variables: systolic blood pressure (BP), diastolic BP, homocysteine, triglycerides, total cholesterol, high-density lipoprotein, low-density lipoprotein, body mass index, serum cortisol, glycosylated hemoglobin, albumin, creatinine clearance, and C-reactive protein. High-risk thresholds were determined based on biological cutoffs of each biomarker. One point was assigned for each biomarker reading above cutoff and were summated to obtain AL score; score =4 was considered high. Results: Mean age of glaucoma patients was 60.82+/-6.26 and 60.14+/-6.72 years in controls ( P =0.602). All components of AL score (except C-reactive protein) had higher values in glaucoma patients. There was a statistically significant difference in homocysteine ( P =0.001), total cholesterol ( P =0.037), high-density lipoprotein ( P =0.005), and glycosylated hemoglobin ( P =0.003). Mean AL score was 4.68+/-2.09 in glaucoma patients and 3.32+/-1.34 in controls ( P <0.001). There was significant association of high AL score with older age ( P =0.006), low socioeconomic status ( P =0.020), and glaucoma severity ( P =0.001). Negative correlation was seen between AL and retinal nerve fiber layer thickness (Right Eye: r =-0.37, P <0.001; Left Eye: r =-0.298, P <0.001) and visual field mean deviation (Right Eye: r =-0.469, P <0.001; Left Eye: r =-0.520, P <0.001). Conclusions: Glaucoma patients exhibited allostatic overload indicating physiological dysregulation to chronic stress although additional research is required to establish causality. A holistic approach with lifestyle modifications to reduce chronic stress should be an integral part of managing glaucoma patients as it would serve both to possibly reduce or prevent disease progression and improve overall health outcomes.