Cardiology Research, ISSN 1923-2829 print, 1923-2837 online, Open Access
Article copyright, the authors; Journal compilation copyright, Cardiol Res and Elmer Press Inc
Journal website https://www.cardiologyres.org

Original Article

Volume 13, Number 3, June 2022, pages 144-153

Habitual Hot-Tub Bathing and Cardiovascular Risk Factors in Patients With Type 2 Diabetes Mellitus: A Cross-Sectional Study

Tables

Table 1. The Clinical and Laboratory Characteristics of the Enrolled Patients
 
VariablesData obtained (n)Mean ± SD, n (%)
BMI: body mass index; HbA1c: hemoglobin A1c; AST: aspartate aminotransferase; ALT: alanine aminotransferase; γGTP: γ-glutamyl transferase; HDL-C: high-density lipoprotein-cholesterol; LDL-C: low-density lipoprotein-cholesterol; eGFR: estimated glomerular filtration rate; SD: standard deviation.
N1,2971,297
Gender (male)1,297713 (55%)
Age (years)1,29766.9 ± 13.6
Body height (cm)1,183161 ± 10
Body weight (kg)1,22167.1 ± 16.5
BMI (kg/m2)1,16025.9 ± 5.3
Waist circumference (cm)26294 ± 15
Systolic blood pressure (mm Hg)984133 ± 16
Diastolic blood pressure (mm Hg)97974 ± 12
Plasma glucose (mg/dL)1,230157 ± 53
HbA1c (%)1,2757.17 ± 1.14
AST (IU/L)1,23427 ± 14
ALT (IU/L)1,22028 ± 23
γGTP (IU/L)1,05243 ± 71
Total cholesterol (mg/dL)983185 ± 35
HDL-C (mg/dL)1,21555 ± 15
LDL-C (mg/dL)795104 ± 27
Triglyceride (mg/dL)1,224151 ± 122
eGFR (mL/min/1.73 m2)1,20970 ± 22
History of coronary artery diseases1,29786 (7%)
History of cerebral infarction1,29771 (5%)
Result of questionnaire
  Frequency of hot-tub bathing (times/week)1,2974.2 ± 2.7
  Duration of hot-tub bathing (min)1,16816 ± 14
  Presence of hot-tub in residence (yes)1,1151,114 (99.9%)

 

Table 2. The Baseline Medications for Diabetes, Hypertension and Dyslipidemia in the Enrolled Patients
 
Medications, number of medicationsN (%), mean ± SD
DPP-4: dipeptidyl peptidase-4; SGLT2: sodium-glucose cotransporter 2; GLP-1: glucagon-like peptide-1; ACE: angiotensin-converting enzyme; SD: standard deviation.
Medications for diabetes
  Insulin201 (15.5%)
  Metformin559 (43.1%)
  Sulfonylurea160 (12.3%)
  Glinides72 (5.6%)
  Thiazolidinedione261 (20.1%)
  Alpha-glucosidase inhibitors204 (15.7%)
  DPP-4 inhibitors796 (61.4%)
  SGLT2 inhibitors312 (24.1%)
  GLP-1 receptor agonists115 (8.9%)
  No medication for diabetes188 (14.5%)
  Number of hypoglycemic agents2.1 ± 1.4
Medication for hypertension
  ACE inhibitors9 (0.7%)
  Angiotensin II receptor blockers591 (45.6%)
  Calcium channel blockers511 (39.4%)
  Diuretics103 (7.9%)
  Alpha blockers16 (1.2%)
  Beta blockers58 (4.5%)
  No medication for hypertension557 (42.9%)
  Number of antihypertensive agents1.0 ± 1.1
Medication for dyslipidemia
  Statins680 (52.4%)
  Ezetimibe151 (11.6%)
  Fibrates56 (4.3%)
  No medication for dyslipidemia478 (36.9%)
  Number of hypolipidemic agents1.7 ± 0.8
Antiplatelet drugs189 (14.6%)

 

Table 3. Pearson’s Simple Correlations Between the Frequency of Hot-Tub Bathing and Metabolic Parameters
 
RP
BMI: body mass index; HbA1c: hemoglobin A1c; AST: aspartate aminotransferase; ALT: alanine aminotransferase; γGTP: γ-glutamyl transferase; HDL-C: high-density lipoprotein-cholesterol; LDL-C: low-density lipoprotein-cholesterol; eGFR: estimated glomerular filtration rate.
Age (years)0.098< 0.001
Body weight (kg)-0.0890.002
BMI (kg/m2)-0.104< 0.001
Waist circumference (cm)-0.1650.014
Systolic blood pressure (mm Hg)-0.0490.127
Diastolic blood pressure (mm Hg)-0.118< 0.001
Plasma glucose (mg/dL)-0.0800.005
HbA1c (%)-0.0780.005
AST (IU/L)0.0220.441
ALT (IU/L)0.0080.771
γGTP (IU/L)-0.0450.144
Total cholesterol (mg/dL)-0.0050.868
HDL-C (mg/dL)0.0070.795
LDL-C (mg/dL)0.0140.693
Triglyceride (mg/dL)-0.0370.192
eGFR (mL/min/1.73 m2)0.0260.360

 

Table 4. The Comparisons of Patient Characteristics and Medications Among Three Groups Divided by the Frequency of Hot-Tub Bathing
 
Frequency of hot-tub bathing (per week)≥ 4 (Group 1)< 4, ≥ 1 (Group 2)< 1 (Group 3)P
DPP-4: dipeptidyl peptidase-4; SGLT2: sodium-glucose cotransporter 2; GLP-1: glucagon-like peptide-1; ACE: angiotensin-converting enzyme; M: male; F: female.
N (gender: M/F)693 (386/307)415 (235/180)189 (92/97)0.163
Age (years)67.5 ± 13.268.0 ± 13.662.3 ± 13.7< 0.001
History of coronary artery diseases44 (6.3%)26 (6.3%)16 (8.5%)0.547
History of cerebral infarction45 (6.5%)19 (4.6%)7 (3.7%)0.204
Duration of hot-tub bathing (min)16 ± 1116 ± 1415 ± 130.617
Medications for diabetes
  Insulin101 (14.6%)73 (17.6%)27 (14.3%)0.359
  Metformin287 (41.4%)185 (44.6%)87 (46.0%)0.399
  Sulfonylurea81 (11.7%)59 (14.2%)24 (12.7%)0.339
  Glinides40 (5.8%)24 (5.8%)8 (4.2%)0.693
  Thiazolidinedione140 (20.2%)88 (21.2%)33 (17.5%)0.566
  Alpha-glucosidase inhibitors114 (16.5%)67 (16.1%)23 (12.2%)0.344
  DPP-4 inhibitors417 (60.2%)273 (65.8%)104 (55.0%)0.098
  SGLT2 inhibitors157 (22.7%)104 (25.1%)51 (27.0%)0.394
  GLP-1 receptor agonists51 (7.4%)39 (9.4%)25 (13.2%)0.038
  No medication for diabetes112 (16.2%)47 (11.3%)29 (15.3%)0.081
  Number of hypoglycemic agents2.0 ± 1.42.2 ± 1.52.0 ± 1.40.078
Medication for hypertension
  ACE inhibitors4 (0.6%)3 (0.7%)2 (1.1%)0.776
  Angiotensin II receptor blockers311 (44.9%)202 (48.7%)78 (41.3%)0.206
  Calcium channel blockers279 (40.3%)169 (40.7%)63 (33.3%)0.180
  Diuretics53 (7.6%)37 (8.9%)13 (6.9%)0.634
  Alpha blockers10 (1.4%)6 (1.4%)0 (0%)0.251
  Beta blockers35 (5.1%)18 (4.3%)5 (2.6%)0.361
  No medication for hypertension294 (42.4%)170 (41.0%)93 (49.2%)0.152
  Number of antihypertensive agents1.0 ± 1.01.1 ± 1.01.0 ± 1.00.090
Medication for dyslipidemia
  Statins355 (51.2%)217 (52.3%)108 (57.1%)0.352
  Ezetimibe83 (12.0%)54 (13.0%)14 (7.4%)0.127
  Fibrates33 (4.8%)15 (3.6%)8 (4.2%)0.660
  No medication for dyslipidemia261 (37.7%)154 (37.1%)63 (33.3%)0.545
  Number of hypolipidemic agents0.79 ± 0.730.81 ± 0.750.80 ± 0.680.887
Antiplatelet drugs100 (14.4%)65 (15.7%)24 (12.7%)0.542

 

Table 5. The Comparisons of Metabolic Parameters Among Three Groups Divided by the Frequency of Hot-Tub Bathing
 
Frequency of hot-tub bathing (per week)≥ 4 (Group 1)< 4, ≥ 1 (Group 2)< 1 (Group 3)P
Comparisons of variables between the three groups were performed by one-way analysis of variance (ANOVA) and Tukey’s multiple comparison test. Data are expressed as mean ± SD. BMI: body mass index; HbA1c: hemoglobin A1c; AST: aspartate aminotransferase; ALT: alanine aminotransferase; γGTP: γ-glutamyl transferase; HDL-C: high-density lipoprotein-cholesterol; LDL-C: low-density lipoprotein-cholesterol; eGFR: estimated glomerular filtration rate; SD: standard deviation; M: male; F: female.
N (gender: M/F)693 (386/307)415 (235/180)189 (92/97)0.163
Age (years)67.5 ± 13.268.0 ± 13.662.3 ± 13.7< 0.001
Body weight (kg)66.2 ± 15.667.1 ± 16.970.0 ± 18.60.026
BMI (kg/m2)25.5 ± 5.026.0 ± 5.426.7 ± 6.00.025
Waist circumference (cm)92 ± 1494 ± 16101 ± 170.012
Systolic blood pressure (mm Hg)133 ± 15132± 18134 ±170.412
Diastolic blood pressure (mm Hg)73 ± 1275 ± 1277 ± 130.001
Plasma glucose (mg/dL)153 ± 50160 ± 54162 ± 620.057
HbA1c (%)7.10 ± 0.977.20 ± 1.117.36 ± 1.670.012
AST (IU/L)27 ± 1425 ± 1228 ± 320.090
ALT (IU/L)28 ± 2126 ± 2229 ± 300.147
γGTP (IU/L)41 ± 4740 ± 4956 ± 1440.048
Total cholesterol (mg/dL)185 ± 33183 ± 35190 ± 420.179
HDL-C (mg/dL)55 ± 1556 ± 1655 ± 160.855
LDL-C (mg/dL)102 ± 32106 ± 36112 ± 360.431
Triglyceride (mg/dL)148 ± 125183 ± 35190 ± 420.275
eGFR (mL/min/1.73 m2)70 ± 2269 ± 2169 ± 240.424

 

Table 6. The Results of Multiple Regression Analysis, Which Showed Variables Independently Associated With HbA1c, Diastolic Blood Pressure and BMI
 
Independent variablesβSEStandardized βP
aMultiple regression analysis with HbA1c as the dependent variable. (R = 0.521, P < 0.001). bMultiple regression analysis with diastolic blood pressure as the dependent variable. (R = 0.453, P < 0.001). cMultiple regression analysis with BMI as the dependent variable. (R = 0.562, P < 0.001). β: coefficient; SE: standard error; BMI: body mass index; HbA1c: hemoglobin A1c; ALT: alanine aminotransferase; HDL-C: high-density lipoprotein-cholesterol; LDL-C: low-density lipoprotein-cholesterol; eGFR: estimated glomerular filtration rate.
Analysis with HbA1c as the dependent variablea
  Gender0.0230.0830.0090.784
  Age0.0060.0030.0650.098
  BMI-0.0010.009-0.0030.946
  ALT0.0080.0020.139< 0.001
  HDL-C0.0030.0030.0350.339
  LDL-C0.0070.0010.179< 0.001
  Triglyceride0.0010.0000.0720.044
  Insulin use0.6090.1170.186< 0.001
  Number of hypoglycemic agents0.3070.0300.363< 0.001
  Frequency of hot-tub bathing (per week)-0.0360.015-0.0780.020
Analysis with diastolic blood pressure as the dependent variableb
  Gender4.3310.9980.178< 0.001
  Age-0.2060.046-0.222< 0.001
  BMI0.2050.1110.0870.066
  ALT0.0410.0260.0710.113
  HDL-C0.0310.0370.0380.396
  LDL-C0.0390.0160.0990.016
  Triglyceride0.0010.0040.0070.865
  eGFR0.0530.0250.0940.035
  Insulin use- 1.4121.279-0.0440.270
  Frequency of hot-tub bathing- 0.5020.183-0.1100.006
Analysis with BMI as the dependent variablec
  Gender-1.2040.314-0.115< 0.001
  Age-0.1290.014-0.323< 0.001
  Diastolic blood pressure0.0270.0140.0620.050
  ALT0.0440.0080.185< 0.001
  HDL-C-0.0750.011-0.212< 0.001
  Triglyceride0.0010.0010.0280.382
  Number of hypoglycemic agents0.3160.1180.0860.008
  Number of hypolipidemic agents-0.0340.209-0.0050.870
  Number of antihypertensive agents0.8180.1520.160< 0.001
  Frequency of hot-tub bathing-0.1440.057-0.0740.012