Association with Longevity of Phosphatidylinositol 3-Kinase Regulatory Subunit 1 Gene Variants Stems from Protection against Mortality Risk in Men with Cardiovascular Disease

Abstract

<b><i>Introduction:</i></b> Genetic variation in the phosphatidylinositol 3-kinase reregulatory subunit 1 gene (<i>PIK3R1</i>) is associated with longevity. <b><i>Objective:</i></b> The aim of the study was to determine whether cardiovascular disease (CVD) affects this association. <b><i>Methods:</i></b> We performed a longitudinal study of longevity-associated <i>PIK3R1</i> single-nucleotide polymorphism <i>rs7709243</i> genotype by CVD status in 3,584 elderly American men of Japanese ancestry. <b><i>Results:</i></b> At baseline (1991–1993), 2,254 subjects had CVD and 1,314 did not. The follow-up until Dec 31, 2019 found that overall, men with a CVD had higher mortality than men without a CVD (<i>p</i> = 1.7 × 10⁻⁵). However, survival curves of CVD subjects differed according to <i>PIK3R1</i> genotype. Those with longevity-associated <i>PIK3R1 TT</i>/<i>CC</i> had survival curves similar to those of subjects without a CVD (<i>p</i> = 0.11 for <i>TT</i>/<i>CC</i>, and <i>p</i> = 0.054 for <i>TC</i>), whereas survival curves for CVD subjects with the <i>CT</i> genotype were significantly attenuated compared with survival curves of subjects without a CVD (<i>p</i> = 0.0000012 compared with <i>TT</i>/<i>CC</i>, and <i>p</i> = 0.0000028 compared with <i>TC</i>). Men without CVD showed no association of longevity-associated genotype with life span (<i>p</i> = 0.58). Compared to subjects without any CVD, hazard ratios for mortality risk were 1.26 (95% CI, 1.14–1.39; <i>p</i> = 0.0000043) for <i>CT</i> subject with CVD and 1.07 (95% CI 0.99–1.17; <i>p</i> = 0.097) for <i>CC</i>/<i>TT</i> subjects with CVD. There was no genotypic effect on life span for 1,007 subjects with diabetes and 486 with cancer. <b><i>Conclusion:</i></b> Our study provides novel insights into the basis for <i>PIK3R1</i> as a longevity gene. We suggest that the <i>PIK3R1</i> longevity genotype attenuates mortality risk in at-risk individuals by protection against cellular stress caused by CVD.