Obesity-associated metabolic changes influence resting and peak heart rate in women and men

Figures & data

Table I. Clinical characteristics of the study population and in women and men separately.

Variable	All (n = 241)	Women (n = 132)	Men (n = 109)
Age (years)	49 ± 9	50 ± 9*	48 ± 9
Weight (kg)	96.5 ± 16.4	90.7 ± 15.2^†	103.6 ± 15.0
Height (cm)	173 ± 10	166.8 ± 6.5^†	180.3 ± 7.0
BMI (kg/m^2)	32.2 ± 4.3	32.6 ± 4.6	31.8 ± 3.8
Obesity (%)	65.1	65.9	64.2
Metabolic syndrome (%)	40.1	32.5*	49.1
Hypertension (%)	41.2	43.0	39.0
Diabetes mellitus (%)	11.9	11.4	12.6
Impaired glucose tolerance (%)	7.5	8.0	6.8
HOMA-IR (units)	4.8 ± 8.9	4.1 ± 5.1	5.6 ± 11.9
Use of anti-hypertensive drugs (%)	61.1	55.6	68.3
Current smoking (%)	14.4	12.1	17.3
Heart rate (beats/minute)	69 ± 11	70 ± 10	68 ± 12
Systolic blood pressure (mmHg)	132 ± 16	130 ± 17*	134 ± 14
Diastolic blood pressure (mmHg)	84 ± 9	82 ± 9*	85 ± 9
Systolic ABP (mmHg)	123 ± 12	121 ± 13^†	125 ± 11
Diastolic ABP (mmHg)	78 ± 8	76 ± 8^†	80 ± 7
Mean ABP (mmHg)	93 ± 9	92 ± 9^†	95 ± 7
Physical activity/week (hours)	3.8 ± 2.7	3.9 ± 2.7	3.6 ± 2.6
Waist circumference (cm)	108.1 ± 10.9	105.9 ± 11.2^†	110.9 ± 9.9
Hip circumference (cm)	114.6 ± 11.1	117.7 ± 12.8^†	110.8 ± 6.9
Fat mass (kg)	35.3 ± 10.8	38.5 ± 9.8^†	31.2 ± 10.7
Muscle mass (kg)	57.4 ± 12.2	49.2 ± 5.9^†	67.6 ± 10.1
Relative muscle mass (%)	60 ± 8	55 ± 4^†	66 ± 9
Fasting serum glucose (mmol/L)	5.6 ± 1.2	5.4 ± 1.0*	5.8 ± 1.4
Triglycerides (mmol/L)	1.6 ± 1.0	1.3 ± 0.8^†	1.8 ± 1.0
Serum cholesterol (mmol/L)	5.4 ± 1.0	5.5 ± 1.0	5.4 ± 1.1
Serum HDL-cholesterol (mmol/L)	1.2 ± 0.3	1.4 ± 0.3^†	1.1 ± 0.2
Serum LDL-cholesterol (mmol/L)	3.7 ± 1.0	3.6 ± 0.9	3.8 ± 1.0
HbA1c (%)	5.6 ± 0.6	5.6 ± 0.5	5.7 ± 0.7
Haemoglobin (g/dL)	14.5 ± 1.3	13.7 ± 0.8^†	15.4 ± 1.0
Serum creatinine (μmol/L)	72.8 ± 13.3	65.6 ± 9.3^†	81.4 ± 12.1

*p < 0.05; ^†p < 0.01: difference between women and men.

BMI, Body mass index; HOMA-IR, insulin resistance from homeostatic model assessment; ABP, Ambulatory blood pressure; HDL, High-density lipoprotein; LDL, Low-density-lipoprotein; HbA_1c, Haemoglobin A_1c.

Figure 1. (upper panel) Univariate correlations of higher resting HR in the total population and in women and men separately. (lower panel) Univariate correlations of higher peak exercise HR in the total population and in women and men separately. HDL, High-density-lipoprotein; HbA1c, Haemoglobin A1c; HOMA-IR, insulin resistance from homeostatic model assessment; ABP, Ambulatory blood pressure; DBP, Diastolic blood pressure; SBP, Systolic blood pressure; BMI, Body mass index; LDL, Low-density-lipoprotein; RER, Respiratory exchange ratio; METs, Metabolic equivalents; VO2max, peak oxygen uptake

Table II. Multivariate regression analyses of resting HR in the total study population and in women and men separately.

Variable	Total population		Women		Men
	Unadjusted	Adjusted	Unadjusted	Adjusted	Unadjusted	Adjusted
Multiple R^2 for model		0.39		0.05		0.46
HOMA-IR (units)	0.21^†	0.14*			0.30^†	0.25*
HbA1c (%)	0.29^†	0.11
Fat mass (kg)	0.15*	− 0.01
Metabolic syndrome	0.26^†	0.20^†	0.15	0.17	0.41^†	0.30^†
Hypertension	0.23^†	0.16^†			0.32^†	0.29^†
Female sex	0.12	0.99^†
Age (years)			0.13	0.16	0.25^†	0.15
Relative muscle mass (%)					− 0.21*	− 0.20*
Diabetes mellitus					0.30^†	0.16
Sex–HR interaction term		0.89^†

*p < 0.05; ^†p < 0.01.

Coefficients represent the change in outcome for 1 beats/minutes change in HR at rest.

HOMA-IR, insulin resistance from homeostatic model assessment; HbA_1c, Haemoglobin A_1c.

Table III. Characteristics from exercise testing in the total study population and in women and men separately.

Variable	Total population	Women	Men
Heart rate (beats/minute)	69 ± 11	70 ± 10	68 ± 12
Peak heart rate (beats/minute)	179 ± 19	179 ± 19	179 ± 19
METs	8.8 ± 2.3	7.8 ± 1.7^†	10.0 ± 2.3
VO2max (ml/kg/min)	31.2 ± 7.7	27.5 ± 5.6^†	35.6 ± 7.6
RER (VCO2/VO2)	1.3 ± 0.4	1.3 ± 0.3	1.4 ± 0.4
Systolic BP before start (mmHg)	141 ± 17	141 ± 18	141 ± 17
Systolic BP at peak exercise (mmHg)	188 ± 25	185 ± 23	191 ± 28

*p < 0.05; ^†p < 0.01: difference between women and men.

METs, Metabolic equivalents; VO₂max, peak oxygen uptake; RER, Respiratory exchange ratio; BP, blood pressure.

Table IV. Multivariate regression analyses of peak HR in the total study population and in women and men separately.

Variable	Total population		Women		Men
	Unadjusted	Adjusted	Unadjusted	Adjusted	Unadjusted	Adjusted
Multiple R^2 for model		0.23		0.30		0.36
VO2max (ml/kg/min)	0.27^†	0.27^†			0.42^†	0.37^†
Female sex	0.02	0.48^†
Age (years)	− 0.41^†	− 0.32^†	− 0.40^†	− 0.42^†	− 0.44^†	− 0.30^†
Hypertension	− 0.24^†	− 0.08
HbA1c (%)			− 0.26^†	− 0.19*
Systolic ABP (mmHg)			− 0.14	0.17
Obesity			0.15	− 0.18*
RER (VCO2/VO2)			0.20*	0.16
Heart rate (beats/minute)			0.05	0.08	− 0.06	0.11
Physical activity/week (hours)					− 0.20	− 0.21*
Metabolic syndrome					− 0.20*	− 0.09
Sex–HR interaction term		0.27*

*p < 0.05; ^†p < 0.01.

Coefficients represent the change in outcome for 1 beats/minutes change in HR at peak.

VO₂max, peak oxygen uptake; HbA_1c, Haemoglobin A_1c; ABP, Ambulatory blood pressure; RER, Respiratory exchange ratio.