Autonomic neuropathy in nondiabetic offspring of type 2 diabetic subjects is associated with urinary albumin excretion rate and 24-h ambulatory blood pressure: the Fredericia Study

Insulin resistance is independently associated with cardiovascular autonomic neuropathy in type 2 diabetes

AIMS/INTRODUCTION

Diabetic cardiovascular autonomic neuropathy (DCAN) seriously threatens the prognosis and quality of life of patients with type 2 diabetes mellitus, associated with increased mortality. The present study aimed to investigate the relevant risk factors of DCAN.

MATERIALS AND METHODS

The present study enrolled a total of 109 patients with type 2 diabetes mellitus. DCAN was defined as a score of at least 2 points in Ewing tests. The updated homeostasis model assessment of insulin resistance (HOMA2-IR) based on fasting C-peptide was calculated to reflect insulin resistance. Logistic regression analysis, interaction and stratified analyses were used to investigate the relationship between HOMA2-IR or other indicators and DCAN. Receiver operating characteristic analysis was carried out to estimate the discriminative value of the variables independently associated with DCAN and to determine the optimal cut-off point of these models to screen DCAN.

RESULTS

The HOMA2-IR levels were significantly higher in patients with DCAN, and tended to be worsened with the progression of the DCAN. Logistic regression analysis showed an independent association between HOMA2-IR (odds ratio 39.30, 95% confidence interval 7.17-215.47) and DCAN. HOMA2-IR (area under the curve 0.878, 95% confidence interval 0.810-0.946; cut-off value 1.735) individually predicted DCAN significantly higher than the other independent risk factors individually used, whereas models combining HOMA2-IR and other risk factors did not significantly boost the diagnostic power.

CONCLUSIONS

Insulin resistance is independently associated with DCAN. HOMA2-IR presents to be a highly accurate and parsimonious indicator for DCAN screening. Patients with HOMA2-IR >1.735 are at a high risk of DCAN; thus, priority diagnostic tests should be carried out for these patients for timely integrated intervention.

The haptoglobin 2-2 genotype is associated with cardiac autonomic neuropathy in type 1 diabetes: the RETRO HDLc study

AIM

The haptoglobin (Hp) 2-2 genotype has been shown to increase the risk of coronary artery disease, kidney dysfunction and mortality from cardiovascular and renal causes in type 1 diabetes (T1D). Similar associations, however, have not been observed in those without diabetes. As cardiac autonomic neuropathy (CAN) is a cardiovascular disease risk factor, we assessed the presence of an association between the Hp 2-2 genotype and CAN.

METHODS

The study included 216 individuals with childhood-onset T1D and 200 individuals with normal glucose tolerance (NGT) of similar age and gender distribution to their counterparts with T1D. CAN was assessed using an electrocardiogram as an abnormal, age-specific, heart rate response to deep breathing. Multivariable logistic regression models were used to assess the association between the Hp 2-2 genotype and CAN.

RESULTS

Compared with NGT, participants with T1D had a similar proportion of Hp 2-2 carriers (41.5% vs. 32.0%, p = 0.05) but a greater CAN prevalence (28.2% vs. 5.0%, p < 0.0001). In multivariable logistic regression models, those carrying the Hp 2-2 genotype had significantly higher odds of CAN compared with Hp 1-1 or Hp 2-1 carriers (OR = 2.27, p = 0.01). The presence of T1D (OR = 4.20, p = 0.0003), hypertension (OR = 2.08, p = 0.03), eGFR (OR = 0.98, p = 0.01) and WBC count (OR = 1.21, p = 0.02) were also associated with CAN. There was no T1D by Hp interaction (p = 0.92), although in stratified analyses, the Hp-CAN association was significant only in T1D.

CONCLUSIONS

The Hp 2-2 genotype was independently associated with greater odds of CAN in T1D though no definitive conclusions could be made in NGT.

Effect of yoga on cardiac autonomic dysfunction and insulin resistance in non-diabetic offspring of type-2-diabetes parents: A randomized controlled study

OBJECTIVE

The present study was aimed to determine the effect of yoga program on cardiac autonomic dysfunction and insulin resistance in non-diabetic offspring of diabetes parents.

METHODS

A randomized passive-controlled study was conducted on 64 non-diabetic offspring of type-2-diabetes parents (mean-age:25.17years). Yoga group participants received yoga training for 8 weeks. Heart-rate variability (HRV) indices: low frequency (LF), high frequency (HF) and LF/HF ratio; fasting blood glucose (FBG), oral glucose tolerance test (OGTT) and insulin resistance (IR) were estimated at baseline and after 8-weeks of intervention.

RESULTS

We found a significant decrease in LF (p = 0.005), LF/HF ratio (p = 0.004), IR (p < 0.001), OGTT (p = 0.003) and increase in HF (p = 0.022) in yoga group participants. Control group participants did not show any significant change in any variables.

CONCLUSIONS

Improvement in cardiac autonomic function and insulin resistance by yoga training implies that yoga can reduce the risk of development of diabetes in offspring of diabetes parents.

Determinants and impact of masked hypertension in offspring of patients with diabetes: relation with coronary flow and cardiac function

OBJECTIVE

We aimed to evaluate the prevalence, determinants and clinical impact of masked hypertension in offspring of patients with diabetes. Masked hypertension was defined according to guidelines as daytime ambulatory blood pressure monitoring "ABPM" ≥135/85 mmHg and clinic BP <140/90 mmHg.

METHODS

100 nondiabetic offspring of patients with diabetes and 60 offspring of healthy people were enrolled; 24-h ABPM was applied to evaluate mean 24-h systolic/diastolic blood pressure "BP", daytime, nighttime and night dipping readings. Left ventricular parameters and coronary flow reserve of the left anterior descending artery (induced by adenosine 0.14 mg/kg/min) was calculated in all offspring.

RESULTS

29% of offspring of patients with diabetes had masked hypertension compared to only 3.3% offspring in healthy people (p < 0.001). Compared with those without masked hypertension, offspring with masked hypertension had a significantly reduced coronary flow reserve (p < 0.001), significantly higher E/e' (p < 0.01), [a surrogate marker of left ventricular filling pressure], more microalbuminuria (p < 0.01), and higher values of high-sensitive C-reactive protein "CRP" (p < 0.001). Multivariate regression analysis showed that, fasting blood glucose, and high-sensitive CRP, were independently associated with masked hypertension, whilst daytime systolic BP and non-dipping systolic BP were the strongest predictors for masked hypertension. Logistic regression analysis revealed that masked hypertension was independently associated with reduced coronary flow reserve (p < 0.0001) and diastolic dysfunction (p < 0.001).

CONCLUSION

Masked hypertension is prevalent in offspring of patients with diabetes and significantly associated with reduced coronary flow reserve and left ventricular diastolic dysfunction. These findings suggest that offspring of patients with diabetes constitute a high risk group and deserve close follow up, mainly with the use of ABPM.

Decreased β-Cell Function is Associated with Cardiovascular Autonomic Neuropathy in Chinese Patients Newly Diagnosed with Type 2 Diabetes

The influence of β-cell function on cardiovascular autonomic neuropathy (CAN), an important diabetes-related complication, is still unclear. In this study, we aimed to investigate the association between residual β-cell function and CAN in patients newly diagnosed with type 2 diabetes. We enrolled 90 newly-diagnosed type 2 diabetic patients and 37 participants with normal glucose tolerance as controls. The patients were divided into a CAN+ group (diabetic patients with CAN, n = 20) and a CAN− group (diabetic patients without CAN, n = 70) according to the standard Ewing battery of tests. Fasting and postprandial plasma glucose, insulin, and C-peptide were measured. Homeostasis model assessment-beta cells (HOMA-B) and HOMA-insulin resistance (IR) were calculated. The prevalence of CAN in this population was 22.2%. Compared with the CAN− group, the CAN+ group had significantly lower fasting plasma insulin (6.60 ± 4.39 vs 10.45 ± 7.82 μ/L, P = 0.029), fasting C-peptide (0.51 ± 0.20 vs 0.82 ± 0.51 nmol/L, P = 0.004), and HOMA-B (21.44 ± 17.06 vs 44.17 ± 38.49, P = 0.002). Fasting C-peptide was correlated with the Valsalva ratio (r = 0.24, P = 0.043) and the 30:15 test (r = 0.26, P = 0.023). Further analysis showed that fasting C-peptide (OR: 0.041, 95% CI 0.003–0.501, P = 0.012) and HOMA-B (OR: 0.965, 95% CI 0.934–0.996, P = 0.028) were independently associated with cardiovascular autonomic nerve function in this population. The patients with fasting C-peptide values < 0.67 nmol/L were more likely to have CAN than those with C-peptide levels ≥0.67 nmol/L (OR: 6.00, 95% CI 1.815–19.830, P = 0.003). A high prevalence of CAN was found in patients with newly-diagnosed type 2 diabetes. Decreased β-cell function was closely associated with CAN in this population.

Risk factors for autonomic and somatic nerve dysfunction in different stages of glucose tolerance

AIM

The present study evaluates autonomic and somatic nerve function in different stages of glucose tolerance and its correlation with different cardio-metabolic parameters.

MATERIAL AND METHODS

Four hundred seventy-eight subjects, mean age 49.3±13.7years and mean BMI 31.0±6.2kg/m2, divided according to glucose tolerance: 130 with normal glucose tolerance (NGT), 227 with prediabetes (125 with impaired fasting glucose (IFG) and 102 with isolated impaired glucose tolerance (iIGT)), and 121 with newly-diagnosed T2D (NDT2D), were enrolled. Glucose tolerance was studied during OGTT. Antropometric indices, blood pressure, HbA1c, serum lipids, hsCRP and albumin-to-creatinine ratio were assessed. Body composition was estimated by a bioimpedance method (InBody 720, BioSpace). Tissue AGEs accumulation was assessed by skin autofluorescence (AGE-Reader-DiagnOpticsTM). Electroneurography was performed by electromyograph Dantec Keypoint. Cardiovascular autonomic neuropathy (CAN) was assessed by ANX-3.0 method applying standard clinical tests.

RESULTS

CAN was found in 12.3% of NGT, 19.8% of prediabetes (13.2% of IFG and 20.6% of iIGT), and 32.2% of NDT2D. The prevalence of diabetic sensory polyneuropathy (DSPN) was 5.7% in prediabetes and 28.6% in NDT2D. The panel of age, QTc interval, waist circumference, diastolic blood pressure, and 120-min plasma glucose was related to sympathetic activity (F [5451]=78.50, p<0.001). The panel of age, waist circumference, and QTc interval was related to parasympathetic power (F [3453]=132.26, p<0.001). HbA1c and age were related to sural SNAP (F [2454]=15.12, p<0.001). HbA1c and AGEs were related to sural SNCV (F [2454]=12.18, p<0.001).

CONCLUSIONS

Our results demonstrate a high prevalence of autonomic and sensory nerve dysfunction in early stages of glucose intolerance. Age, postprandial glycemia, central obesity, diastolic blood pressure and QTc interval outline as predictive markers of CAN; hyperglycemia, glycation and age of DSPN.

Alterations in heart rate variability during everyday life are linked to insulin resistance. A role of dominating sympathetic over parasympathetic nerve activity?

Aims

To evaluate the role of the autonomic nervous system (ANS) in the development of insulin resistance (IR) and assess the relationship between IR and activity of ANS using power spectrum analysis of heart rate variability (HRV).

Subjects and methods

Twenty-three healthy first-degree relatives of patients with type 2 diabetes (R) and 24 control subjects without family history of diabetes (C) group-matched for age, BMI and sex were included. Insulin sensitivity (M value) was assessed by hyperinsulinemic (56 mU/m²/min) euglycemic clamp. Activity of the ANS was assessed using power spectrum analysis of HRV in long-term recordings, i.e., 24-h ECG monitoring, and in short-term recordings during manoeuvres activating the ANS. Computed tomography was performed to estimate the amount and distribution of abdominal adipose tissue.

Results

Insulin sensitivity (M value, mg/kg lbm/min) did not differ significantly between the R and C groups. Total spectral power (P_tot) and very low-frequency (P_VLF) power was lower in R than C during 24 h ECG-recordings (p = 0.02 and p = 0.03). The best fit multiple variable linear regression model (r² = 0.37, p < 0.001 for model) indicated that body composition (BMI) and long-term low to high frequency (LF/HF) power ratio (std β = −0.46, p = 0.001 and std β = −0.28, p = 0.003, respectively) were significantly and independently associated with the M value.

Conclusion

Altered heart rate variability, assessed by power spectrum analysis, during everyday life is linked to insulin resistance. The data suggest that an increased ratio of sympathetic to parasympathetic nerve activity, occurring via both inherited and acquired mechanisms, could potentially contribute to the development of type 2 diabetes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0411-8) contains supplementary material, which is available to authorized users.

Cardiovascular autonomic neuropathy (CAN) in patients of type 2 diabetes mellitus: a tertiary care hospital based study

INTRODUCTION

Diabetes mellitus (DM) is a clinical syndrome characterized by hyperglycemia due to absolute or relative insulin deficiency. Cardiovascular autonomic neuropathy invokes potentially life threatening outcomes especially in poorly controlled diabetic patients. However, there is scarcity of epidemiological data for CAN in poorly controlled type 2 diabetic patients in Pakistan.

OBJECTIVE

The objective of this study is to assess the frequency of cardiovascular autonomic neuropathy (CAN) in patients with poorly controlled type 2 diabetes mellitus in Pakistan.

STUDY DESIGN

Descriptive cross-sectional.

SETTING

Department of Medicine, Liquate University Hospital, Hyderabad/Jamshoro, Sindh, Pakistan.

DURATION

February to November 2012.

SAMPLING TECHNIQUE

Non-probability purposive.

MATERIAL AND METHOD

This study included 207 patients, who all met the inclusion criteria and gave an informed consent for inclusion in the study. All the patients in the study were evaluated for CAN using four different clinical tests- Resting heart rate, test for orthostatic hypotension, hand gripping test and QTc interval on ECG. Resting Heart Rate of more than 100 beats per minute was taken as abnormal. Orthostatic hypotension was defined as a fall of systolic blood pressure >20 mmHg and/or diastolic blood pressure >10 mmHg on change of posture. The patients were asked to squeeze a small ball in hand gripping test and an increase in diastolic blood pressure <15 mmHg was considered abnormal. ECG recording with QTc interval >440 ms was considered abnormal or prolonged. Patients were labeled as CAN +ve if any two or more than two of the above listed tests were found positive/abnormal.

RESULTS

In our study, 76 out of 207 (36.7%) of the patients with poorly controlled type 2 diabetes mellitus were found to have cardiovascular autonomic neuropathy (CAN).

CONCLUSION

Cardiac autonomic dysfunctions are common in poorly controlled type 2 diabetes.

The hypothalamic clock and its control of glucose homeostasis

The everyday life of mammals, including humans, exhibits many behavioral, physiological and endocrine oscillations. The major timekeeping mechanism for these rhythms is contained in the central nervous system (CNS). The output of the CNS clock not only controls daily rhythms in sleep/wake (or feeding/fasting) behavior but also exerts a direct control over glucose metabolism. Here, we show how the biological clock plays an important role in determining early morning (fasting) plasma glucose concentrations by affecting hepatic glucose production and glucose uptake, as well as glucose tolerance, by determining feeding-induced insulin responses. Recently, large-scale genetic studies in humans provided the first evidence for the involvement of disrupted (clock gene) rhythms in the pathogenesis of type 2 diabetes.

Olanzapine shifts the temporal relationship between the daily acrophase of serum prolactin and cortisol concentrations rhythm in healthy men

Treatment with the atypical antipsychotic drug olanzapine is frequently associated with development of obesity and insulin resistance. Treatment-induced weight gain has been suggested to be the main contributing factor of diminished insulin sensitivity. This study evaluated the effects of short-term treatment with olanzapine on 12h plasma prolactin and cortisol concentrations in healthy men. The effects of two distinct olanzapine formulations were investigated; the oral standard tablets (OST) and the orally disintegrating tablets (ODT). Recent reports indicate that treatment with the ODT formulation may be less harmful in terms of weight gain than the OST. 12 healthy men (age: 25.1+/-5.5 y) received olanzapine OST (10mg QD, 8 days), olanzapine ODT (10mg QD, 8 days) or no intervention in a randomized cross-over design. On day 8, blood samples were taken every 10min between 0000 and 1200h for determination of cortisol and prolactin concentrations. Treatment with olanzapine OST and ODT similarly increased the 12h mean PRL concentrations and the secreted PRL mass. Both drugs similarly shifted the maximal PRL concentration approximately 3-4h backwards in time. Cortisol secretions rates were lower, but the timing of the cortisol acrophase did not change. Both drugs significantly elevated HOMA index for insulin resistance. In conclusion olanzapine OST and ODT equally elevated the prolactin concentration and significantly shifted its acrophase, thus dissociating PRL and cortisol, while both formulations induced similar insulin resistance as evidenced by the elevated HOMA-IR. Notably, these alterations occurred without a measurable effect on body adiposity.

“Diabetes of the elderly” and type 2 diabetes in younger patients: Possible role of the biological clock

The increased prevalence of type 2 diabetes in the aged has been recognized for a long time. Within the last decades, a growing number of younger subjects and even children are prone to develop type 2 diabetes. In both groups, aged and young, the biological clock, located in the suprachiasmatic nucleus of the hypothalamus (SCN) is malfunctioning as evidenced by disturbed sleep cycles and altered circadian rhythms. While elderly patients have an impaired function of the SCN due to the degeneration of neurons, we propose that in younger subjects the clock loses its "feeling" for internal and external rhythms caused by the modern lifestyle. Sleeping late and less coupled with constant metabolic excess alter both internal and external environmental stimuli to the brain. In response to these alterations, the rhythm of the biological clock is disrupted which may lead to the metabolic syndrome and type 2 diabetes.

Insulin resistance in diabetic nephropathy--cause or consequence?

Insulin resistance (IR) is associated with multiple risk factors for cardiovascular disease. Many studies have shown that IR is present in chronic renal failure (CRF), and recent evidence suggests that IR can also occur in the early stages of renal disease. Patients with diabetic nephropathy (DN) have an increase in cardiovascular mortality, and since IR may be a contributing factor, this emphasizes the importance of a detailed understanding of the mechanisms linking IR and renal dysfunction at different stages of DN. IR can be detected early on in DN, e.g. at the stage of microalbuminuria (MA) and this could indicate a common genetic trait for IR and DN. As DN progresses further, IR is aggravated and it may, in addition to other factors, possibly accelerate the decline in renal function toward end-stage renal disease (ESRD). Several potentially modifiable mechanisms including circulating hormones, neuroendocrine pathways and chronic inflammation, are said to contribute to the worsening of IR. In ESRD, uremic toxins are of major importance. In this review article, we address the association between different stages of DN and IR and attempt to summarize major findings on potential mechanisms linking DN and IR. We conclude that IR is a consequence, and potentially also a cause of DN. In addition, there are probably genetic and environmental background factors that predispose to both IR and DN.

Tracing from fat tissue, liver, and pancreas: a neuroanatomical framework for the role of the brain in type 2 diabetes

The hypothalamus uses hormones and the autonomic nervous system to balance energy fluxes in the body. Here we show that the autonomic nervous system has a distinct organization in different body compartments. The same neurons control intraabdominal organs (intraabdominal fat, liver, and pancreas), whereas sc adipose tissue located outside the abdominal compartment receives input from another set of autonomic neurons. This differentiation persists up to preautonomic neurons in the hypothalamus, including the biological clock, that have a distinct organization depending on the body compartment they command. Moreover, we demonstrate a neuronal feedback from adipose tissue that reaches the brainstem. We propose that this compartment-specific organization offers a neuroanatomical perspective for the regional malfunction of organs in type 2 diabetes, where increased insulin secretion by the pancreas and disturbed glucose metabolism in the liver coincide with an augmented metabolic activity of visceral compared with sc adipose tissue.

A 14-year prospective study of autonomic nerve function in Type 1 diabetic patients: association with nephropathy

AIMS

Prospective studies of autonomic nerve function are rare. We have followed the progression of autonomic dysfunction in relation to nephropathy over 14 years in Type 1 diabetic patients.

METHODS

Autonomic nerve function was assessed by heart-rate responses to deep breathing (E/I ratio) and tilting (acceleration and brake indices) and by the postural blood pressure reaction in 58 patients, 43 of whom were reassessed after 14 years. Nephropathy was evaluated by the degree of albuminuria (albuminuria > 20 micro g/min or > 0.03 g/24 h) and glomerular filtration rate ((51)Cr-EDTA plasma clearance). The acceleration index had deteriorated after 7 years (P = 0.0155), whereas the E/I ratio (P = 0.0070) and the diastolic postural blood pressure reaction (P = 0.0054) had deteriorated 14 years after the baseline examination (age-corrected values). All those with albuminuria at the third examination showed signs of autonomic neuropathy at baseline (10 of 10) compared with only nine of 22 without (P = 0.0016). Multiple regression analysis showed that the association between autonomic dysfunction and future albuminuria was due to the E/I ratio. In addition, individuals with an abnormal postural diastolic blood pressure fall (n = 7) at baseline showed a greater fall in glomerular filtration rate more than others 7-14 years later [29 (16.5) ml/min/1.72 m(2) vs. 11 (9) ml/min/1.72 m(2); P = 0.0074].

CONCLUSION

Autonomic nerve function had deteriorated after 14 years. Autonomic neuropathy and abnormal postural diastolic blood pressure falls at baseline were associated with future renal complications.

Hypothesis: shifting the equilibrium from activity to food leads to autonomic unbalance and the metabolic syndrome

“The stability of the internal environment is the condition that life should be free and independent… So, far from the higher animal being indifferent to the external world, it is on the contrary in a precise and informed relation with it, in such a way that its equilibrium results from a continuous and delicate compensation, established as by the most sensitive of balances.”

Claude Bernard (1865)

Preclinical diabetic cardiomyopathy: relation of left ventricular diastolic dysfunction to cardiac autonomic neuropathy in men with uncomplicated well-controlled type 2 diabetes

Diabetic cardiomyopathy is an ill-defined entity. This study was designed to explore the possible association between left ventricular diastolic dysfunction (LVDD) and cardiac autonomic neuropathy (CAN) independently from metabolic control. Three groups of 10 age-matched men each with well-controlled type 2 diabetes were studied: (1) subjects with normal diastolic function, (2) subjects with LVDD characterized by impaired LV relaxation, and (3) subjects with a more severe form of LVDD characterized by a pseudonormalized pattern of LV filling. No subject had evidence of clinical diabetic complications, coronary artery disease (CAD), hypertension, congestive heart failure, or thyroid or overt renal disease, and all had a negative maximal exercise test. LVDD was evaluated by Doppler echocardiographic and CAN was evaluated using spectral analysis of heart rate variability (HRV; time and frequency domains) from 24-hour Holter recordings. Findings showed that the high frequency power (HF: 0.15 to 0.4 Hz) tends to decrease with worsening diastolic function; 5.0 +/- 0.2 ms(2) (mean +/- SE) in group 1, 4.2 +/- 0.3 ms(2) in group 2, and 3.9 +/- 0.4 ms(2) (P =.03) in group 3, respectively, whereas the low frequency power (LF: 0.04 to 0.15 Hz) was similar between groups. In the time domain, the mean squared differences of the successive RR intervals (rMSDD) also showed the same pattern, ie, 31.0 +/- 2.8 ms, 23.8 +/- 1.6 ms, and 21.5 +/- 2.9 ms in groups 1, 2, and 3, respectively (P =.03). The E/A ratio correlated significantly with indices of parasympathetic modulation (HF; r = 0.448, P =.013; rMSDD: r = 0.457, P =.011; pNN50: r = 0.425, P =.019). LVDD and CAN are associated in patients with otherwise uncomplicated well-controlled type 2 diabetes. The parameters defining these 2 abnormalities may serve to better define diabetic cardiomyopathy as a distinct entity and could eventually become useful prognostic indicators as it has been shown in nondiabetic populations.

Early autonomic dysfunction in glucose-tolerant but insulin-resistant offspring of type 2 diabetic patients

In type 2 diabetes, both insulin resistance and hyperglycemia are considered responsible for autonomic dysfunction, but the specific role of these two abnormalities is not clear. To test the specific role of insulin resistance on autonomic dysfunction, we studied 69 glucose-tolerant offspring of type 2 diabetic patients, comparing the most insulin-resistant tertile (IR) with the most insulin-sensitive tertile (IS) and comparable control subjects, all undergoing the oral glucose tolerance test, impedentiometry, 24-hour blood pressure and ECG monitoring, and an intravenous glucose tolerance test (IVGTT) followed by a euglycemic hyperinsulinemic clamp, with continuous blood pressure and ECG measurements. Sympathovagal balance was evaluated as low- to high-frequency ratio (LF:HF) by spectral analysis on R-R intervals. The change of systolic and diastolic blood pressure was calculated as [(day-night/d)]x100. In IR, the changes of systolic and diastolic blood pressure were significantly lower versus IS (9.2+/-5.0% versus 12.4+/-3.6%, P<0.02; 13.2+/-6.5% versus 17.4+/-5.2%, P<0.02). During the night, LF:HF fall was reduced in IR (43.1+/-21.0 versus 61.4+/-16.9, P<0.02). Hyperinsulinemia (IVGTT) rapidly and significantly increased LF:HF in IR (4.9+/-3.3 versus basal: 2.3+/-1.4, P=0.03) but not in IS. In offspring of type 2 diabetic patients with normal glucose tolerance and normal blood pressure values, insulin resistance is associated with abnormal control of blood pressure and sympathetic activation. Insulin resistance may therefore be responsible for some early derangements of the autonomic nervous tone control and thus contributes to increase the incidence of arterial hypertension and/or diabetes.