TABLE 3.

ASSESSING THE IMPACT OF POSSIBLE CONFOUNDERS ON THE ASSOCIATION BETWEEN OBSTRUCTIVE SLEEP APNEA AND DIABETIC PERIPHERAL NEUROPATHY (BASED ON THE MICHIGAN NEUROPATHY SCREENING INSTRUMENT) USING DIFFERENT LOGISTIC REGRESSION MODELS (FORCED ENTRY METHOD)

Model	Nagelkerke R2	OR	95% CI	P Value
Unadjusted: OSA	0.13	4.09	2.28–7.35	<0.001
Model 1	0.25	2.82	1.44–5.52	0.003
Model 2	0.26	2.76	1.41–5.40	0.003
Model 3	0.25	3.33	1.72–6.47	<0.001
Model 4	0.28	2.77	1.36–5.62	0.005
Model 5	0.29	2.72	1.34–5.55	0.006

Definition of abbreviations: BMI = body mass index; CI = confidence interval; DPN = diabetic peripheral neuropathy; eGFR = estimated glomerular filtration rate; HDL = high-density lipoprotein; OR = odds ratio; OSA = obstructive sleep apnea.

The ORs reported are the odds for having DPN in OSA+ compared with OSA− patients. All patients (n = 234) were included in all models. Models 1, 2, and 3 include only the main possible confounders for the relationship between OSA and DPN, whereas models 4 and 5 are adjusted for all variables in our database.

Model 1: OSA + ethnicity + sex + age at diabetes diagnosis + diabetes duration + eGFR + insulin use + BMI + mean arterial pressure + HbA1c + alcohol intake (units/wk).

Model 2: as model 1 but replacing BMI with waist circumference.

Model 3: as model 1 but replacing BMI with waist hip ratio.

Model 4: OSA + age at diabetes diagnosis + ethnicity + sex + diabetes duration + BMI + alcohol intake + HbA1c+ insulin use + mean arterial pressure + eGFR + PVD + smoking + total cholesterol + triglycerides + HDL + oral antidiabetes treatment + antihypertensive agents + lipid-lowering therapy + antiplatelets + recruitment site.

Model 5: As for model 4 but both BMI and waist circumference included in the model.