Table 2 Multiple linear regression analysis with hearing threshold as the dependent variable and age and NAD + metabolites (NA, NAM, and NAR) as independent variables
From: Blood levels of nicotinic acid negatively correlate with hearing ability in healthy older men
Dependent variable | Independent variable | regression coefficient | 95% lower confidence interval | 95% upper confidence interval | p-value |
|---|---|---|---|---|---|
(A) NA | |||||
R 1000 Hz (dB HL) | NA (μM) | 1610 (2657) | 0.840 (934) | 3220 (4379) | 0.050* (0.004**) |
R 2000 Hz (dB HL) | NA (μM) | 2317 (3782) | 348 (1585) | 4286 (5979) | 0.022* (0.001**) |
L 1000 Hz (dB HL) | NA (μM) | 2179 (2419) | 271 (274) | 4087 (4563) | 0.026* (0.028*) |
L 2000 Hz (dB HL) | NA (μM) | 3257 (5968) | 1306 (3777) | 5208 (8159) | 0.002** (< 0.001***) |
L 4000 Hz (dB HL) | NA (μM) | 1892 (3743) | -319 (519) | 4103 (6966) | 0.091 (0.024*) |
(B) NAM | |||||
L 250 Hz (dB HL) | NAM (μM) | 2.00 (1.34) | 0.752 (-0.00297) | 3.26 (2.68) | 0.002** (0.050) |
L 2000 Hz (dB HL) | NAM (μM) | 2.11 (1.43) | 0.48 (-0.347) | 3.75 (3.21) | 0.013* (0.111) |
(C) NAR | |||||
R 125 Hz (dB HL) | NAR (μM) | -4504 (-14,605) | -10,882 (-31,840) | 1875 (2631) | 0.161 (0.094) |
L 1000 Hz (dB HL) | NAR (μM) | 6197 (7358) | -2783 (-14,109) | 15,176 (28,826) | 0.171 (0.489) |
L 2000 Hz (dB HL) | NAR (μM) | 10,156 (9963) | 679 (-19,773) | 19,633 (39,698) | 0.036* (0.499) |