A total of 174 patients (141 female) with a mean age of 58.50 ± 7.37 years (range: 36–80) were included in the study. There were 93 patients with diabetes mellitus type 2 in the case group with a mean age of 59.86 ± 8.63 years (77 females), and 81 age- and sex-matched non-diabetic individuals with mean age of 56.95 ± 6.31 years (64 female) in the control group. There were no statistically significant differences regarding demographic factors between the two groups (P > 0.05). CAD risk factors such as hypertension and dyslipidemia were more common in the case group compared to the controls (P = 0.002, p = 0.001). Mean duration of diabetes in patients was 8.56 ± 4.50 years. The baseline and clinical characteristics of the study participants are presented in Table 1.
Table 1
Demographic Characteristics of the Participants
Variable | DM (n = 93) | Non-DM (n = 81) | P-value* |
N (%) | N (%) |
Gender | Female | 77 (82.79) | 64 (79.01) | 0.11 |
Male | 16 (17.20) | 17 (20.98) |
Total | 93 (100) | 81 (100) |
HTN | Yes | 31 (34.44) | 47 (58.02) | 0.002 |
No | 59 (65.56) | 34 (41.98) |
Total | 90 (100) | 81 (100) |
Duration of Diabetes | < 5 years | 27 (29.03) | - | - |
≥ 5 years | 66 (70.96) | - |
Total | 93 (100) | - |
Smoking | Yes | 9 (10.11) | 16 (19.75) | 0.07 |
No | 80 (89.89) | 65 (80.25) |
Total | 89 (100) | 81 (100) |
HLP | Yes | 60 (64.51) | 18 (22.22) | < 0.001 |
No | 33 (35.48) | 63 (77.78) |
Total | 93 (100) | 81 (100) |
Type of stress | Treadmill | 17 (18.27) | 16 (18.76) | 0.78 |
DIP | 76 (81.72) | 65 (81.24) |
Total | 93 (100) | 81 (100) |
*Based on Chi-Square Test; HTN = hypertension; HLP = high lipid profit; DIP = dipyridamole.
According to some previous studies, obtained values of QGS (QGS Mean 30.9–80.2, PBW QGS 24, SD 8.6, Entropy 31) and 4DM (Mean 4DM 6.1–10.2, PBW 24, PSD 9.4) were used as a cutoff value for the diagnosis of LVMD (left ventricular myocardial dyssynchrony)(20). Considering PBW in QGS software, LVMD was detected in 8% of diabetics and 16% of non-diabetics (not statistically significant). In 4Dm software these measures were 23.9% and 8.6% for diabetics and non-diabetics respectively. Except for PBW and mean phase in of 4DM software, no statistically significant difference was observed between control and diabetic patients (P < 0.05) (Table 2).
Based on Pearson's test poor correlation exists between findings of QGS and 4DM software (p = 0.04, r = 0.2).
Moreover, the duration of DM was divided into four groups : below 5 years (26 patients), between 5–10 (34), between 10–15 (17) and more than 15 years (16). Kruskal Wallis analysis to assess the impact of duration of DM revealed that as the duration of diabetes is prolonged, especially more than 15 years, the probability of LVMD [PBW in both QGS and 4DM] is increased as well (p = 0.021). However, there were no statistical significant differences between diabetic patients below 15 years, and non-diabetic patients (Figs. 1).Samples of normal and LVDM are shown in Figs. 2 and 3 respectively.
EDVs were in the range of 16 to 137 ml in control group compared to 6 to 95 ml for both diabetic patients and diabetic patients with LVMD, respectively. ESV ranges were 1 to 72, 0 to 40 and 10 to 42 ml for controls, diabetic patients without and with LVMD, respectively. However, no significant differences were observed for quantitative parameters (LVEF, EDV, ESV and LV mass) between these groups (P > 0.05).
Univariate linear regression analysis showed an association between higher EDV-ESV and lower ejection fraction (EF) and presence of diabetes, obesity, smoking and older age (Table 2).
Table 2
Distribution of Demographic and Clinical Characteristics in Diabetic and Non-Diabetic Patients
Variable | All (n = 174) | DM (n = 93) | Non-DM (n = 81) | P-value* |
Mean (SD) | Mean (SD) | Mean (SD) |
Age (year) | 58.50 (10.37) | 59.86 (8.64) | 56.95 (11.31) | 0.21 |
Weight (kg) | 76.34 (13.7) | 77.32 (13.48) | 75.23 (13.96) | 0.35 |
| Median (IQR) | Median (IQR) | Median (IQR) | P-value** |
QGS | | | | |
PBW | 18 (12) | 18 (9) | 18 (12) | 0.25 |
Entropy | 21 (13) | 20 (13.5) | 23 (15) | 0.17 |
PSD | 3.7 (2.7) | 3.35 (2.55) | 3.9 (2.8) | 0.27 |
mean | 143 (22.2) | 146.85 (22.95) | 142 (19.8) | 0.08 |
PFR | 3.1 (1.57) | 3.04 (2) | 3.21 (1.37) | 0.3 |
PFR2 | 1.52 (2.97) | 1.85 (3.38) | 0.91 (2.35) | 0.11 |
MFR3 | 1.33 (0.82) | 1.32 (0.93) | 1.33 (0.61) | 0.58 |
TTPF | 163 (84.5) | 152 (91) | 171 (78) | 0.23 |
PER | -4.33 (0.99) | -4.41 (0.98) | -4.24 (1.01) | 0.25 |
EDV | 49 (27) | 45.5 (24) | 53 (30) | 0.03 |
ESV | 13 (12) | 11 (9) | 15 (13) | 0.01 |
EF | 75 (14) | 76 (12) | 73 (15) | 0.02 |
4DM | | | | |
Mean | 50.2 (14.6) | 51.4 (13.9) | 47.6 (14.4) | 0.009 |
SD | 7.32(3.1) | 7.75(2.8) | 6.85(3.3) | 0.14 |
PBW | 26 (16) | 28 (17) | 24 (12) | 0.02 |
* Based on t-test; ** Based on Mann-Whitney test; IQR = Interquarter Range;
QGS = Quantitative Gated SPECT; PBW = Phase Bandwidth; PSD = Phase Bandwidth;
PFR = Peak Filling Rate; PFR2 = Second Pick Filling Rate; MFR3 = Mean Filling Rate in the first
1/3 of the diastole; TTPF = Time to Peak Filling Rate; PER = Peak Ejection Rate; EDV=
End Diastolic Volume; ESV = End Systolic Volume; EF = Ejection Fraction
Mean duration of DM was also higher in diabetic patients with LVMD compared to those without LVMD (P < 0.05).