Cigarette Smoking Is Associated with Prolongation of the QTc Interval Duration in Patients with Type 2 Diabetes Mellitus

Table 4

Mean values (±SD) of E/I index, BRS measurements, and QTc interval duration during 24-hour, day, and night periods.

Variable	Chronic smokers	Nonsmokers	𝑃
E/I index	1.29 ± 0.15	1.23 ± 0.1	0.085
RBRS (ms mmHg^−1)	9.35 ± 5.97	8.07 ± 3.73	0.287
CBRS (ms mmHg^−1)	8.09 ± 4.57	7.19 ± 4.08	0.388
SE RBRS	0.99 ± 0.78	0.81 ± 0.64	0.308
SE CBRS	0.92 ± 0.87	0.73 ± 0.68	0.313
RBEI	0.294 ± 0.157	0.331 ± 0.121	0.283
CBEI	0.287 ± 0.162	0.327 ± 0.128	0.271
QTc 24 hours (ms)	439.25 ± 26.95	425.05 ± 23.03	0.021
QTc day (ms)	439.14 ± 24.31	427.17 ± 23.99	0.042
QTc night (ms)	440.91 ± 32.3	425.51 ± 24.98	0.033

E/I index: expiration/inspiration index; RBRS: radial baroreflex sensitivity; CBRS: central baroreflex sensitivity; RBEI: radial baroreflex effectiveness index; CBEI: central baroreflex effectiveness index.
CBRS was assessed through the evaluation of the estimated central blood pressure changes on heart rate.
RBRS was assessed through the evaluation of the radial artery blood pressure changes on heart rate.