24-h blood pressure and autonomic function is related to albumin excretion within the normoalbuminuric range in IDDM patients

Abstract

Summary Significant changes in both blood pressure, autonomic function and kidney ultrastructure are observed in insulin-dependent diabetic (IDDM) patients with microalbuminuria. Intervention strategies are evaluated at even earlier stages of disease. Identification of patients at risk of developing microalbuminuria must be based on a thorough knowledge of the relations between key pathophysiological parameters in patients with normoalbuminuria. The aim of the present study was to characterize the interactions of urinary albumin excretion (UAE), 24-h ambulatory blood pressure (AMBP), and sympathovagal balance in a large group of normoalbuminuric IDDM patients. In 117 normoalbuminuric (UAE < 20 m g/min) patients we performed 24-h AMBP (Spacelabs 90 207), with assessment of diurnal blood pressure and heart rate (HR) variation, and short-term (three times 5 min) power spectral analysis of RR interval oscillations, as well as cardiovascular reflex tests (HR variation to deep breathing, postural HR and blood pressure response). Patients with UAE above the median (4.2 m g/min) had significantly higher 24-h systolic and diastolic AMBP (125 ± 10.1/76 ± 7.2 mmHg) compared to the low normoalbuminuric group (120 ± 8.4/74 ± 5.1 mmHg), p < 0.01 and 0.02, respectively. Patients with UAE above the median had significantly reduced short-term RR interval variability including both the high frequency component (5.47 ± 1.36 vs 6.10 ± 1.43 ln ms 2 ), and low frequency component (5.48 ± 1.18 ln ms 2 compared to 5.80 ± 1.41 ln ms 2 ), p < 0.02 and p = 0.04 (ANOVA). In addition, patients with highnormal UAE had reduced mean RR level (faster heart rates) 916 ± 108 compared to 963 ± 140 ms, p < 0.04. These differences were not explained by age, duration of diabetes, gender, level of physical activity, or cigarette smoking. HbA 1 c was significantly higher (8.6 ± 1.2 vs 8.2 ± 1.0 %, p = 0.03) in the group with high normal UAE. Comparing normoalbuminuric IDDM patients with UAE above and below the median value, we found significantly higher AMBP in combination with significant differences in sympathovagal balance and significantly poorer glycaemic control in the group with high-normal albumin excretion. Our data demonstrate interactions between albumin excretion, blood pressure, autonomic function, and glycaemic status, already present in the normoalbuminuric range and may describe a syndrome indicative of later complications. [Diabetologia (1997) 40: 718-725] Keywords Ambulatory blood pressure, autonomic control, heart rate variability, spectral analysis, IDDM, microalbuminuria, diabetic nephropathy

Prediction of albuminuria by different blood pressure measurement methods in type 1 diabetes: a pilot study

“…29 However, when both methods were entered in the same model, HBP lost its significance and nighttime ABP was the only independent predictor of worsening albuminuria. 29 Previous studies in diabetics 30,31 and nondiabetics 22 have shown that nighttime ABP gives the strongest correlations with albuminuria. This was not confirmed in this study, yet the findings do support the view that ABP is superior to clinical and also to home measurements in predicting albuminuria in type 1 diabetes.…”

Ambulatory pulse pressure, decreased nocturnal blood pressure reduction and progression of nephropathy in type 2 diabetic patients

“…Numerous previous studies have established the superiority of 24 h AMBP over conventional office BP measurement for the association with [1,5,15,32,33] and prediction of hypertensive end-organ damage in diabetes [9,34,35]. Moran et al found that office and 24 h systolic AMBP were independently associated with albuminuria in elderly type 2 diabetic patients [4]; however in the longitudinal study mentioned above [9], ambulatory PP predicted progression of albuminuria above and beyond office BP.…”

Usefulness of ambulatory blood pressure monitoring in predicting the presence of autonomic neuropathy in type I diabetic patients

“…14,18 A lot of evidence has been gathered that points to a strong link between nondipping phenomenon and autonomic neuropathy, even with a suggestion of a pathogenetic meaning, 13,[15][16][17]29 though some uncertainty still exists about all the pathogenetic mechanisms involved. Nevertheless, recently in 61 type I diabetic subjects, Stella et al 30 did not find any independent relationship between autonomic neuropathy and nondipping and suggested again a primary link between nondipping and diabetic nephropathy regardless of autonomic neuropathy but modified by low-density lipoprotein cholesterol and hypertension.…”

“…[8][9][10][11][12] Although some uncertainty still persists about the whole pathophysiology of the nondipping phenomenon, a series of studies have allowed to show the main pertinence of nondipping to diabetic autonomic neuropathy. [13][14][15][16][17][18] Notwithstanding, the predictive value of nondipping with regard to the presence of autonomic neuropathy has not been established.…”