Table 3.

Serum magnesium in no retinopathy, non-STDR and STDR groups.

Severity of retinopathy	Number of patients (n)	Serum magnesium (mg/dL) Mean ± SD	95% confidence interval for mean		p value
			Lower	Upper
No diabetic retinopathy	54	1.76 ± 0.22	1.71	1.82	0.031 a
Non-STDR	33	1.68 ± 0.37	1.54	1.81
STDR	17	1.55 ± 0.33	1.39	1.72

SD, standard deviation; STDR, sight-threatening diabetic retinopathy.

^aANOVA test.