title: Central adiposity and decreased heart rate variability in postmenopause: a cross-sectional study.
abstract: OBJECTIVE
  To investigate the impact of waist circumference (WC) on heart rate variability in 87 apparently healthy, postmenopausal women.
  
  
  METHODS
  In this cross-sectional study, time- and frequency-domain heart rate variability indices were determined at rest and during sympathetic stimulation with mental stress. Patients were stratified according to WC ≥ or < 88 cm. The mean (± standard deviation) age was 55 ± 5 years. The median time since menopause was 6 (range 1-22) years. Age and time since menopause were similar.
  
  
  RESULTS
  The mean body mass index was 27.12 ± 4.49 kg/m². Metabolic syndrome was diagnosed in 26 (29.5%) participants. Thirty-eight participants (43.6%) had hypertension. Women with WC ≥ 88 cm had higher body mass index, glucose and insulin (both fasting and after a 75-g oral glucose tolerance test), HOMA, triglycerides, and free androgen index (p < 0.05). The metabolic syndrome was more frequent in women with WC ≥ 88 cm (24.13% vs. 5.74%; p < 0.01). At rest, women with WC ≥ 88 cm presented lower vagal modulation, expressed by a reduction in the mean of all normal RR intervals (mean RR) (p < 0.01) and root mean square of successive differences of adjacent RR intervals (rMSSD) (p < 0.05) than women with WC < 88 cm. Mental stress significantly increased sympathetic modulation in both groups, expressed by reduction in high frequency (HF), increase in low frequency (LF) and LF/F ratio, and reduction in mean RR and rMSSD.
  
  
  CONCLUSIONS
  Less favorable metabolic profile and lower cardiac vagal modulation with preserved sympathetic responsiveness were found in participants with WC ≥ 88 cm, suggesting that central adiposity may be associated with decreased heart rate variability in apparently healthy, postmenopausal women.
authors.affiliation: * Gynecological Endocrinology Unit, Division of Endocrinology.
authors.forename: R
authors.initials: R
authors.lastname: Franz
authors.forename: M A
authors.initials: MA
authors.lastname: Maturana
authors.forename: J A
authors.initials: JA
authors.lastname: Magalhães
authors.forename: R S
authors.initials: RS
authors.lastname: Moraes
authors.forename: P M
authors.initials: PM
authors.lastname: Spritzer
mesh_terms: D050153:Abdominal Fat / Q000503:physiopathology*; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000175:diagnosis; D007328:Insulin / Q000097:blood; D024821:Metabolic Syndrome / Q000175:diagnosis / Q000503:physiopathology; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000503:physiopathology*; D017698:Postmenopause / Q000502:physiology*; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D055105:Waist Circumference
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D007328:Insulin; D014280:Triglycerides; D002784:Cholesterol