Effect of the Administration of Alpha-Lipoic Acid on Contrast Sensitivity in Patients with Type 1 and Type 2 Diabetes

Table 3

Characteristics of contrast sensitivity examinations in T2DM patients with and without ALA supplementation at baseline and after 3 months.

Spatial frequencies	T2DM patients without; ALA supplementation; CS × LC = 132 measurements			T2DM patients with; ALA supplementation; CS × LC = 200 measurements
	Baseline	After 3 months	𝑃 value	Baseline	After 3 months	𝑃 value
A-1.5 cpd
Mean. ± SD	5.7±1.7	5.3±1.7		5.8±1.6	5.7±1.5
Range	1.0–9.0	0.0–9.0	𝑃=0.000^∗∗	0.0–9.0	1.0–9.0	𝑃=0.451
Median	6.0	5.0		6.0	6.0
95% CI	[5.4; 6.0]	[5.0; 5.5]		[5.6; 6.0]	[5.5; 5.9]
B-3 cpd
Mean. ± SD	5.0±1.8	4.7±1.9		5.2±1.7	5.3±1.6
Range	0.0–8.0	0.0–9.0	𝑃=0.001^∗∗	0.0–8.0	0.0–9.0	𝑃=0.7371
Median	5.0	5.0		5.0	5.0
95% CI	[4.7; 5.4]	[4.3; 5.0]		[5.0; 5.5]	[5.0; 5.5]
C-6 cpd
Mean. ± SD	3.9±2.3	3.5±2.2		4.3±2.3	4.4±2.1
Range	0.0–9.0	0.0–8.0	𝑃=0.001^∗∗	0.0–9.0	0.0–9.0	𝑃=0.377
Median	4.0	4.0		5.0	4.5
95% CI	[3.5; 4.3]	[3.1; 3.9]		[3.9; 4.6]	[4.1; 4.7]
D-12 cpd
Mean. ± SD	2.1±2.3	2.1±2.1		2.7±2.2	3.0±2.2
Range	0.0–7.0	0.0–7.0	𝑃=0.866	0.0–8.0	0.0–9.0	𝑃=0.001^∗
Median	1.0	2.0		3.0	3.0
95% CI	[1.7; 2.5]	[1.7; 2.5]		[2.3; 3.0]	[2.7; 3.3]
E-18 cpd
Mean. ± SD	1.2±1.9	1.1±1.8		1.3±2.0	1.6±2.0
Range	0.0–7.0	0.0–7.0	𝑃=0.329	0.0–9.0	0.0–8.0	𝑃=0.013^∗
Median	0.0	0.0		0.0	0.0
95% CI	[0.9; 1.5]	[0.8; 1.4]		[1.0; 1.6]	[1.3; 1.9]

CS × LC: the number of contrast sensitivity measurements of each eye in 4 luminance conditions and under 5 spatial frequencies.
A-1.5, B-3, C-6, D-12, and E-18 cpd: spatial frequencies.
*Statistically significant differences between the baseline examination of T2DM patients with ALA supplementation versus after 3 months.
**Statistically significant differences between the baseline examination of T2DM patients without ALA supplementation versus after 3 months.