Both Prediabetes and Type 2 Diabetes Are Associated With Lower Heart Rate Variability: The Maastricht Study.

Low heart rate variability (HRV), a marker for cardiac autonomic dysfunction, is a known feature of type 2 diabetes, but it remains incompletely understood whether this also applies to prediabetes or across the whole glycemic spectrum. Therefore, we investigated the association among prediabetes, type 2 diabetes, and measures of glycemia and HRV. In the population-based Maastricht Study (n = 2,107; mean ± SD age 59 ± 8 years; 52% men; normal glucose metabolism [n = 1,226], prediabetes [n = 331], and type 2 diabetes [n = 550, oversampled]), we determined 24-h electrocardiogram-derived HRV in time and frequency domains (individual z-scores, based upon seven and six variables, respectively). We used linear regression with adjustments for age, sex, and major cardiovascular risk factors. After adjustments, both time and frequency domain HRV were lower in prediabetes and type 2 diabetes as compared with normal glucose metabolism (standardized β [95% CI] for time domain: -0.15 [-0.27; -0.03] and -0.34 [-0.46; -0.22], respectively, P for trend <0.001; for frequency domain: -0.14 [-0.26; -0.02] and -0.31 [-0.43; -0.19], respectively, P for trend <0.001). In addition, 1-SD higher glycated hemoglobin, fasting plasma glucose, and 2-h postload glucose were associated with lower HRV in both domains (time domain: -0.16 [-0.21; -0.12], -0.16 [-0.21; -0.12], and -0.15 [-0.20; -0.10], respectively; frequency domain: -0.14 [-0.19; -0.10], -0.14 [-0.18; -0.09], and -0.13 [-0.18; -0.08], respectively). Both prediabetes and type 2 diabetes were independently associated with lower HRV. This is further substantiated by independent continuous associations between measures of hyperglycemia and lower HRV. These data strongly suggest that cardiac autonomic dysfunction is already present in prediabetes.

Coopmans C ，Zhou TL ，Henry RMA ，Heijman J ，Schaper NC ，Koster A ，Schram MT ，van der Kallen CJH ，Wesselius A ，den Engelsman RJA ，Crijns HJGM ，Stehouwer CDA ... -  《-》

Prediabetes and Type 2 Diabetes Are Associated With Generalized Microvascular Dysfunction: The Maastricht Study.

Type 2 diabetes (T2DM) is associated with an increased risk of cardiovascular disease. This can be partly explained by large-artery dysfunction, which already occurs in prediabetes ("ticking clock hypothesis"). Whether a similar phenomenon also applies to microvascular dysfunction is not known. We therefore tested the hypothesis that microvascular dysfunction is already present in prediabetes and is more severe in T2DM. To do so, we investigated the associations of prediabetes, T2DM, and measures of hyperglycemia with microvascular function measured as flicker light-induced retinal arteriolar dilation and heat-induced skin hyperemia. In the Maastricht Study, a T2DM-enriched population-based cohort study (n=2213, 51% men, aged [mean±standard deviation] 59.7±8.2 years), we determined flicker light-induced retinal arteriolar %-dilation (Dynamic Vessel Analyzer), heat-induced skin %-hyperemia (laser-Doppler flowmetry), and glucose metabolism status (oral glucose tolerance test; normal glucose metabolism [n=1269], prediabetes [n=335], or T2DM [n=609]). Differences were assessed with multivariable regression analyses adjusted for age, sex, body mass index, smoking, physical activity, systolic blood pressure, lipid profile, retinopathy, estimated glomerular filtration rate, (micro)albuminuria, the use of lipid-modifying and blood pressure-lowering medication, and prior cardiovascular disease. Retinal arteriolar %-dilation was (mean±standard deviation) 3.4±2.8 in normal glucose metabolism, 3.0±2.7 in prediabetes, and 2.3±2.6 in T2DM. Adjusted analyses showed a lower arteriolar %-dilation in prediabetes (B=-0.20, 95% confidence interval -0.56 to 0.15) with further deterioration in T2DM (B=-0.61 [-0.97 to -0.25]) versus normal glucose metabolism (P for trend=0.001). Skin %-hyperemia was (mean±standard deviation) 1235±810 in normal glucose metabolism, 1109±748 in prediabetes, and 937±683 in T2DM. Adjusted analyses showed a lower %-hyperemia in prediabetes (B=-46 [-163 to 72]) with further deterioration in T2DM (B=-184 [-297 to -71]) versus normal glucose metabolism (P for trend=0.001). In addition, higher glycohemoglobin A1c and fasting plasma glucose were associated with lower retinal arteriolar %-dilation and skin %-hyperemia in fully adjusted models (for glycohemoglobin A1c, standardized B=-0.10 [-0.15 to -0.05], P<0.001 and standardized B=-0.13 [-0.19 to -0.07], P<0.001, respectively; for fasting plasma glucose, standardized B=-0.09 [-0.15 to -0.04], P<0.001 and standardized B=-0.10 [-0.15 to -0.04], P=0.002, respectively). Prediabetes, T2DM, and measures of hyperglycemia are independently associated with impaired microvascular function in the retina and skin. These findings support the concept that microvascular dysfunction precedes and thus may contribute to T2DM-associated cardiovascular disease and other complications, which may in part have a microvascular origin such as impaired cognition and heart failure.

Sörensen BM ，Houben AJ ，Berendschot TT ，Schouten JS ，Kroon AA ，van der Kallen CJ ，Henry RM ，Koster A ，Sep SJ ，Dagnelie PC ，Schaper NC ，Schram MT ，Stehouwer CD ... -  《-》

Heart Rate Variability and Cardiac Autonomic Dysfunction: Prevalence, Risk Factors, and Relationship to Arterial Stiffness in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) Study.

To determine whether prior type 2 diabetes (T2D) treatment or glycemic control over time are independently associated with heart rate variability (HRV) and whether the presence of cardiac autonomic dysfunction is associated with arterial stiffness in young adults with youth-onset T2D enrolled in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study. Heartbeats over 10 min were measured to derive the normal R-Rs (NN intervals). Outcomes included the standard deviation of the NN intervals (SDNN), the root mean square differences of successive NN intervals (RMSSD), percent of NN beats that differ by more than 50 ms (PNN50), and the low-frequency (LF) power domain, high-frequency (HF) power domain, and their ratio (LF:HF). Autonomic dysfunction was defined as ≥3 of 5 abnormal HRV indices compared with obese controls from a separate study. A total of 397 TODAY participants were evaluated 7 years after randomization. TODAY participants had reduced HRV (SDNN 58.1 ± 29.6 ms vs. controls 67.1 ± 25.4 ms; P < 0.0001) with parasympathetic loss (RMSSD 53.2 ± 36.7 ms vs. controls 67.9 ± 35.2 ms; P < 0.0001) with sympathetic overdrive (LF:HF ratio 1.4 ± 1.7 vs. controls 1.0 ± 1.1; P < 0.0001). Cardiac autonomic dysfunction was present in 8% of TODAY participants, and these participants had greater pulse wave velocity compared with those without dysfunction (P = 0.0001). HRV did not differ by randomized treatment, but higher hemoglobin A1c (HbA1c) over time was independently associated with lower SDNN and RMSSD and higher LF:HF ratio after adjustment for age, race-ethnicity, sex, and BMI. Young adults with youth-onset T2D show evidence of cardiac autonomic dysfunction with both parasympathetic and sympathetic impairments that are associated with higher HbA1c.

Shah AS ，El Ghormli L ，Vajravelu ME ，Bacha F ，Farrell RM ，Gidding SS ，Levitt Katz LE ，Tryggestad JB ，White NH ，Urbina EM ... -  《-》

Compromised cardiac autonomic function in non-diabetic subjects with 1 h post-load hyperglycemia: a cross-sectional study.

Monea G ，Jiritano R ，Salerno L ，Rubino M ，Massimino M ，Perticone M ，Mannino GC ，Sciacqua A ，Succurro E ，Fiorentino TV ，Andreozzi F ... -  《Cardiovascular Diabetology》

Heart Rate, Autonomic Function, and Future Changes in Glucose Metabolism in Individuals Without Diabetes: The Whitehall II Cohort Study.

Autonomic nervous system dysfunction is associated with impaired glucose metabolism, but the temporality of this association remains unclear in individuals without diabetes. We investigated the association of autonomic function with 5-year changes in glucose metabolism in individuals without diabetes. Analyses were based on 9,000 person-examinations for 3,631 participants without diabetes in the Whitehall II cohort. Measures of autonomic function included 5-min resting heart rate and six heart rate variability (HRV) indices. Associations between baseline autonomic function measures and 5-year changes in fasting and 2-h plasma glucose, serum insulin concentrations, insulin sensitivity (insulin sensitivity index [ISI0-120] and HOMA of insulin sensitivity), and β-cell function (HOMA of β-cell function) were estimated in models adjusting for age, sex, ethnicity, metabolic factors, and medication. A 10-bpm higher resting heart rate was associated with 5-year changes in fasting and 2-h insulin and ISI0-120 of 3.3% change (95% CI 1.8; 4.8), P < 0.001; 3.3% change (1.3; 5.3), P = 0.001; and -1.4% change (-2.4; -0.3), P = 0.009, respectively. In models adjusted for age, sex, and ethnicity, higher baseline values of several HRV indices were associated with a 5-year decrease in fasting and 2-h insulin and ISI0-120. However, significance was lost by full adjustment. A majority of HRV indices exhibited a trend toward higher values being associated with lower insulin levels and higher insulin sensitivity. Higher resting heart rate in individuals without diabetes is associated with future unfavorable changes in insulin levels and insulin sensitivity. Associations may be mediated via autonomic function; however, results are inconclusive. Resting heart rate may be a risk marker for future pathophysiological changes in glucose metabolism.

Hansen CS ，Færch K ，Jørgensen ME ，Malik M ，Witte DR ，Brunner EJ ，Tabák AG ，Kivimäki M ，Vistisen D ... -  《-》