24-h Urinary Albumin Excretion Research Articles

Urinary albumin excretion and 24-hour blood pressure as predictors of pre-eclampsia in Type I diabetes.

To evaluate the value of 24-h blood pressure monitoring compared to office blood pressure and urinary albumin excretion in predicting pre-eclampsia in Type I (insulin-dependent) diabetes mellitus. The study included 136 consecutive pregnancies in Caucasian women with Type I diabetes before gestation without diabetic nephropathy, anamnestic hypertension or early abortion. Values of urinary albumin excretion and office blood pressure before pregnancy and the HbA1C value at the time of conception were obtained. Microalbuminuria was defined as urinary albumin excretion of 30-300 mg/24 h in two out of three consecutive urine samples. Single measurements of 24-h urinary albumin excretion, office blood pressure and HbA1C were done five 5 times during pregnancy. In a subgroup of 74 women 24-h blood pressure measurements were done at 10 and 28 weeks of gestation. Pre-eclampsia was defined as office blood pressure higher than 140/90 mmHg accompanied by proteinuria above 0.3 g/24 h later than 20 weeks of gestation. Urinary albumin excretion and systolic blood pressure were higher before and throughout pregnancy in 14 women developing pre-eclampsia compared with women remaining normotensive (p <0.001; p < 0.05, respectively). By logistic regression analysis the best predictor for pre-eclampsia was microalbuminuria before pregnancy (p < 0.05) with no additive predictive effect of 24-h blood pressure or office blood pressure measurement. The night:day ratio of blood pressure was similar in the two groups. Microalbuminuria before pregnancy is the strongest predictor of pre-eclampsia in Type I diabetes. Measuring 24-h blood pressure early in pregnancy did not improve the ability to identify women at risk.

White coat hypertension in type 1 diabetic patients without nephropathy

The aim of our study was to determine the prevalence of white coat hypertension (WCH) in type 1 diabetic patients. Therefore, ambulatory blood pressure monitoring (ABPM) and 24-h urinary albumin excretion (UAE) were determined in 47 patients with type 1 diabetes mellitus (27 with new diagnosis of hypertension by office blood pressure (BP) measurement and 20 with normotension). WCH was diagnosed in 20 patients (74%). Patients with WCH presented higher values of systolic and diastolic BP and UAE than normotensive patients. The results indicate that in type 1 diabetes mellitus WCH is very frequent. Thus, WCH may represent a potential risk for the development of diabetic complications, mainly diabetic nephropathy.

Correlation of acetylator phenotype with peripheral, autonomic and central neuropathy in Northern Indian non-insulin-dependent diabetes mellitus patients

Genetic susceptibility to diabetic neuropathy has been suspected and tentatively explored; however, diabetic autonomic and central neuropathies are poorly investigated areas. Previous trials correlating types of diabetes and diabetic neuropathy with acetylator dimorphisms have not been conclusive. The present study was designed to test peripheral neuropathy, autonomic neuropathy and integrity of central conduction pathways in patients of non-insulin-dependent diabetes mellitus (NIDDM), and to correlate the findings with the acetylator phenotype. Twenty-six patients of NIDDM with stable glycaemic control and 11 age- and sex-matched control subjects were recruited, clinically examined and investigated with glycaemic and lipid profile, renal function tests, nerve conduction studies (sensory and motor), auditory brain stem evoked responses (ABERs) and somatosensory evoked potentials (SEPs). Acetylator status of the subjects was determined by sulphadimidine test. Out of 26 NIDDM patients, eight (30.7%; group 1A) were slow acetylators and 18 (69.3%; group 1B) were fast acetylators. The distribution of slow and rapid acetylators in both the groups was similar. Glycaemic and lipid profiles and 24-h urinary albumin excretion in groups 1A and 1B were also similar. Motor nerve conduction velocity, latency of F wave, sensory nerve conduction and amplitudes of sensory nerve action potentials were not different between fast and slow acetylator NIDDM patients. On testing for ABERs, there were no statistically significant differences in peak latencies of waves I, III and V; interpeak latencies (IPLs) I-III, III-V and I-V; amplitude of waves I, III and V on both sides between NIDDM patients and controls. However, peak latencies of wave III (P < 0.01), wave V (P < 0.005), IPLs I-III and I-V (P < 0.005), IPLs III-V (P < 0.05), and amplitudes of wave I (P < 0.05) and wave V (P < 0.05) on the left side were significantly different in slow acetylator NIDDM patients. Increase on the right side for the same group was statistically significant for IPLs I-III and I-V (P < 0.05). SEPs showed no statistically significant difference between NIDDM patients and controls, and slow and fast acetylator NIDDM patients. No significant association of acetylator status with peripheral neuropathy in NIDDM subjects was observed in the present study. However, central neural conduction, primarily tested by ABERs, was significantly delayed in slow acetylators compared with fast acetylator NIDDM patients. Hence, there may be a predisposition to neuropathy in this group of patients, and such a predisposition may be better detected by studying central rather than peripheral nervous conduction pathways in NIDDM patients.

Hyperfiltration in African-American patients with type 2 diabetes. Cross-sectional and longitudinal data.

Hyperfiltration may play a role in the development of diabetic nephropathy. African-American patients with diabetes have more than a fourfold increase in end-stage renal disease. The purpose of this study is to evaluate the impact of hyperfiltration on renal function in African-American patients with type 2 diabetes. Renal function of 194 African-American patients with diagnosed type 2 diabetes from 1 month to 36 years was assessed by studies of isotopic glomerular filtration rate (GFR), serum creatinine, creatinine clearance, and 24-h urinary albumin excretion rates. Thirty-four patients with a duration of diagnosed type 2 diabetes from 1 month to 10 years were found to have hyperfiltration (GFR > or = 140 ml.min-1.1.73 m-2). Fifteen of these patients received longitudinal follow-up of renal function for as long as 15 years after the initial study. Hyperfiltration is present in 15 (36%) of 42 patients whose duration of diagnosed type 2 diabetes is < 1 year, and it persists for up to 10 years in 14-20% of patients with diagnosed type 2 diabetes. Patients with hyperfiltration are younger than their counterparts without hyperfiltration when matched for duration of diagnosed diabetes. When followed over time, those patients with hyperfiltration were not more likely to develop impaired renal function as measured by GFR or creatinine clearance. Hyperfiltration does not identify patients at risk for deterioration in renal function.

Ambulatory blood pressure and urinary albumin excretion in diabetic (non–insulin-dependent and insulin-dependent) hypertensive patients: Relationships at baseline and after treatment by the angiotensin converting enzyme inhibitor trandolapril

The aim of the present study was to examine the relationships between ambulatory blood pressure (ABPM) and urinary albumin excretion (UAE) in diabetic (non–insulin dependent [NIDDM] and insulin-dependent [IDDM]) hypertensives at baseline and after treatment by an angiotensin converting enzyme (ACE) inhibitor. After a 3-week placebo period, patients were treated for 16 weeks with trandolapril, 2 to 4 mg/day. The UAE and blood pressure (mercury sphygmomanometer and 24-h ABPM) were measured at baseline and repeated on trandolapril. Predictive factors of abnormal UAE (24-h UAE ≥30 mg) were determined using univariate and multivariate analysis (logistic regression). Predictors of UAE decrease were also searched. One hundred seventy-one patients entered the analysis. Baseline office BP was 164 ± 14/97 ± 6 mm Hg and 24-h BP was 142 ± 17/83 ± 10 mm Hg. Seventy-four patients (43%) had UAE ≥30 mg. Independent risk factors for abnormal UAE were nighttime diastolic BP (odds ratio [OR] = 4.1, confidence interval [CI] = 2.0 to 8.6, P = .0001), diabetes duration (OR = 2.4, CI = 1.1 to 5.0, P = .025), and presence of retinopathy (OR = 3.2, CI = 1.0 to 10.0, P = .047). Conversely, office BP level was not significantly related to UAE. On treatment, office BP levels decreased to 143 ± 13/82 ± 8 mm Hg ( P < .0001) and 24-h BP levels to 134 ± 17/78 ± 9 mm Hg ( P < .0001). In the abnormal UAE group, UAE significantly decreased from 76 to 50 mg/day ( P = .006). After treatment, independent predictive factors of abnormal UAE were: on-drug fasting plasma glucose (OR = 3.5, CI = 1.7 to 7.4, P = .0009) and on-drug nighttime diastolic BP (OR = 3.5, CI = 1.7 to 7.4, P = .001). The only predictor of UAE decrease was a 24-h systolic BP decrease (OR = 2.3, CI = 1.3 to 4.3, P = .007). We conclude that in diabetic hypertensives with abnormal UAE, trandolapril exhibited a sustained 24-h antihypertensive effect and provided a consistent reduction of microalbuminuria. This study confirmed the superiority of ABPM over clinical BP to predict target organ damage.

Proteinuria is still useful for the screening and diagnosis of overt diabetic nephropathy.

To assess the performance of urinary total protein measurements in timed 24-h urine collection (24-h UP) and in a diurnal random urine specimen (RUS) for the screening and diagnosis of overt diabetic nephropathy. A total of 167 diabetic patients (20 type 1 and 147 type 2 diabetic patients; 78 women and 89 men), aged 20-84 years, collected 217 timed 24-h urine specimens. Albumin was measured by immunoturbidimetry, total protein by sulfosalicylic acid technique, and creatinine by Jaffe's method. According to the timed 24-h urinary albumin excretion rate (UAER), samples were divided into three groups: normoalbuminuric (NORMO) (UAER < 20 micrograms/min; n = 84), microalbuminuric (MICRO) (UAER 20-200 micrograms/min; n = 78), and macroalbuminuric (MACRO) (UAER > or = 200 micrograms/min; n = 55). Eighty-six patients also collected 105 RUSs (NORMO, n = 47; MICRO, n = 37; MACRO, n = 21), and urinary protein concentration (UPC) and urinary protein-to-creatinine ratio (UPCR) were measured. The receiver operating characteristics (ROC) curve approach was used to analyze the performance of the diagnostic tests. Spearman's coefficient of correlation of 24-h UAER versus 24-h UP was 0.95 (P < 0.001), and of 24-h UAER versus UPC and UPCR were 0.77 and 0.72, respectively (P < 0.001). The calculated areas (+/- SEM) under the ROC curve for the diagnosis of over diabetic nephropathy were 0.9987 +/- 0.001 for 24-h UP, 0.9926 +/- 0.006 for UPC, and 0.9751 +/- 0.014 for UPCR. In the ROC curves, the first points with 100% sensitivity were 541 mg (95.7% specificity) for 24-h UP, 431 mg/l (92.9% specificity) for UPC, and 0.2 (76.2% specificity) for UPCR. Measurements of proteinuria presented almost perfect accuracy for the screening and diagnosis of overt diabetic nephropathy. Protein measurement in spot urine is a reliable and simple method for the screening and diagnosis of overt diabetic nephropathy.

Angiotensinogen T235 and ACE insertion/deletion polymorphisms associated with albuminuria in Chinese type 2 diabetic patients.

Genetic polymorphisms of the renin-angiotensin system (RAS) have been implicated in the pathogenesis of diabetic proteinuria. Ethnic differences in the frequencies of these genotypes have also been reported. To date, most of these studies have been performed in white and Japanese populations. In this study, we examined the associations between albuminuria and RAS genetic polymorphisms in Chinese patients with type 2 diabetes. In a case-control study, the ACE insertion/deletion (I/D) gene, the angiotensinogen (AGT) gene (M235T), and the angiotensin II (AII) type 1 receptor gene (AT1 A1166C) were examined in 110 Chinese type 2 diabetic patients. Increased urinary albumin excretion (UAE) was defined as > or = 30 mg/day on at least two occasions during a 6-week study period. Compared with whites, there were high frequencies of the AGT TT genotype in Chinese control subjects (120/183 = 70%) and type 2 diabetic patients (74/110 = 67%). The frequencies of the MM genotype were 5 and 3%, respectively, and those of the ACE DD genotype were 13 and 10%, respectively. Although 9% of subjects carried the C allele, the AT1 CC genotype was not found in either group. Chinese type 2 diabetic patients with increased albuminuria (n = 56) had higher systolic blood pressure (160 +/- 26 mmHg vs 145 +/- 27 mmHg, P < 0.001) than the normoalbuminuric patients (n = 54). Both the AGT TT genotype (78.6% [44/56] vs. 55.6% [30/54], odds ratio [OR]: 3.0 [1.3-6.8]) and the T allele (88% [99/112] vs. 77% [83/108], OR: 2.5 [1.3-5.4]) were associated with an increased risk of albuminuria. Patients with the AGT TT genotype (n = 74) had higher 24-h UAE than those with the MT or MM genotypes (n = 36) (median: 37.8 mg/day vs. 17.8 mg/day, P < 0.01). This association remained significant in patients with normotension (56 mg/day [n = 19] for patients with the TT genotype vs. 22 mg/day [n = 14] for those with the MT/MM genotype, P = 0.03). The D allele carriers (DD or DI, n = 61) had higher serum ACE activities (75.5 +/- 29 U/l vs. 60.5 +/- 36.3 U/l, P < 0.01) than the noncarriers (II genotype). The median 24-h UAE also tended to be higher in the D allele carriers (38.9 mg/day vs. 21.4 mg/day, P = 0.07). The lowest UAE was observed in patients with the MM/MT/II genotype (16.3 mg/day [n = 18]) and the highest, in patients with the TT/DD/DI genotype (52.3 mg/day [n = 43]). No association was found between the TT genotype or D allele and hypertension. The high frequencies of the TT genotype and T allele in Chinese populations may contribute to the high prevalence of albuminuria in patients with type 2 diabetes. The possibility of synergism between the AGT TT genotype and the ACE D allele should also be explored.

The Relationship of Hyperinsulinemic State to Left Ventricular Hypertrophy, Microalbuminuria, and Physical Fitness in Borderline and Mild Hypertension

The relationship of the hyperinsulinemic state to left ventricular hypertrophy, left ventricular geometric patterns, microalbuminuria, and physical fitness were studied in 52 middle-aged unmedicated men with borderline and mild hypertension. Left ventricular mass index and relative wall thickness were assessed by echocardiography. Physical fitness was determined by symptom-limited maximal treadmill stress testings. The urinary concentration of microalbumin and C-peptide was measured in 24-h urine samples by radioimmunoassey. The 24-h urinary C-peptide excretion rate was correlated with left ventricular mass index (r = 0.46), relative wall thickness (r = 0.41), treadmill time (r = −0.35), normalized treadmill time (r = −0.52), systolic blood pressure at peak exercise (r = 0.29), and 24-h urinary microalbumin excretion (r = 0.48). Stepwise multiple regression analysis identified the left ventricular mass index, the 24-h urinary albumin excretion, and the normalized treadmill time as variables in the equation for the 24-h urinary C-peptide excretion. Thus, the hyperinsulinemic state is related to left ventricular hypertrophy, microalbuminuria, and impaired physical fitness in patients with borderline and mild hypertension.

Effect of 14 years of antihypertensive treatment on renal function and urinary albumin excretion in primary hypertension

The effects on blood pressure (BP), renal function, and urinary albumin excretion (UAE) of 14 years of antihypertensive treatment were studied and compared to the changes seen with normal aging. The studied groups included randomly selected men with newly diagnosed primary hypertension at baseline (n = 23) and normotensive (NT) men of the same age (n = 11). The hypertensives (HT) were treated with β-blockers either as monotherapy or combined with diuretics or hydralazine. Glomerular filtration rate (GFR; inulin clearance), renal blood flow (RBF, para-aminohippurate clearance), renal vascular resistance (RVR), and 24-h UAE were determined. The two groups were investigated at baseline (before treatment) and after 7 and 14 years. At baseline, BP and RVR were significantly increased and RBF was significantly decreased in the HT over that in the NT. The BP in the HT was significantly reduced after 7 years of treatment and a further but nonsignificant reduction to 139 ± 14 88 ± 6 mm Hg (mean ± SD) was seen after 14 years. GFR in the HT was significantly reduced from 103 ± 15 mL/min to 84 ± 19 mL/min (mean ± SD) after 7 years, but no further reduction was seen after 14 years. During the 14 years RBF decreased and RVR increased in the HT but these changes were of the same magnitude as in the NT. The UAE did not change significantly during the study. In conclusion, good blood pressure control with conventional antihypertensive treatment in mild to moderate primary hypertension seems to protect the kidney from progressive decline in GFR and increase in UAE. The increase in RVR and the decrease in RBF seen during 14 years of antihypertensive treatment was of the same magnitude as that seen with normal aging.

Albuminuria and 24-h Ambulatory Blood Pressure in Normoalbuminuric and Microalbuminuric NIDDM Patients. A longitudinal study

To assess the long-term relationships between 24-h ambulatory blood pressure (AMBP), urinary albumin excretion (UAE) rate, and metabolic control in non-insulin-dependent diabetes mellitus (NIDDM) patients with normo- and microalbuminuria. We conducted a prospective study of 23 NIDDM patients (11 with normoalbuminuria and 12 with microalbuminuria) receiving standard clinical care, including antihypertensive treatment, attending the outpatient clinic and 8 healthy control subjects. Twenty-four-hour AMBP and UAE were measured synchronously in addition to fasting plasma glucose, HbA1c, and serum creatinine at baseline and after 4.6 (4.2-5.1) years [mean (range)]. Baseline systolic, but not diastolic, 24-h AMBP was significantly higher in diabetic patients compared with control subjects (146/80 [16/11] vs. 133/78 [9/9] mmHg, P < 0.05), but was similar in normoalbuminuric (143/81 [11/11] mmHg) and microalbuminuric (148/80 [20/10] mmHg) patients during strict blood pressure control. The annual increase in 24-h AMBP was equivalent in diabetic patients (0.6/-0.2 [2.6/1.5] mmHg/year) and control subjects (0.7/0.2 [1.2/1.4] mmHg/year, NS) and not significantly different from zero. Overall UAE did not change in control subjects (5.6 [1.6] vs. 4.4 [1.9]) (geometric mean [antilog SD]) or in the normoalbuminuric (8.7 [1.7] vs. 11.3 [3.0] micrograms/min) and microalbuminuric (35.7 [2.1] vs. 34.5 [3.2] micrograms/min) patients. In diabetic patients, the annual change in UAE correlated significantly with the annual change in the systolic (r = 0.61, P < 0.002) and diastolic (r = 0.54, P < 0.008) 24-h AMBP. In microalbuminuric patients, only the annual increase in systolic 24-h AMBP correlated significantly with the annual change in UAE (r = 0.71, P = 0.010), whereas in the normoalbuminuric patients, only the annual increase in diastolic 24-h AMBP and the annual change in UAE were significantly correlated (r = 0.66, P = 0.026). In a stepwise multiple linear regression analysis, the annual progression in albuminuria in NIDDM patients was significantly determined by increases in systolic (parameter estimate 0.018, SE 0.006, P < 0.008) as well as in diastolic 24-h AMBP (parameter estimate 0.026, SE 0.011, P < 0.033). In an outpatient clinical setting, 24-h AMBP is similar in NIDDM patients with normo- and microalbuminuria. Alterations in both 24-h AMBP and UAE are on average moderate and equivalent compared with those in healthy control subjects. Although the average change in albuminuria is small, a progression in albuminuria relates to increments in both systolic and diastolic 24-h AMBP.

24-h ambulatory blood pressure, daytime and nighttime urinary albumin and retinol-binding protein excretion in type I diabetic patients

We studied 24-h ambulatory blood pressure (SBP, DBP), actual glycemic control assessed from seven blood glucose measurements, 16-h daytime and 8-h nighttime urinary excretion of albumin (UAE) and retinol-binding protein (URBP) in 20 normoalbuminuric (group A, nighttime UAE < 20 μg/min) and 20 microalbuminuric and low-proteinuric type I diabetic patients (group B, nighttime UAE 20–500 μg/min) matched for age and diabetes duration. Glycemic control was similar in the two groups. Daytime and nighttime SBP and DBP were higher in group B compared to group A ( p < 0.01). Nighttime decrease in SBP and DBP correlated with nighttime decrease in UAE in group B ( p < 0.05, p < 0.001), but not in group A. There was no correlation between BP and actual glycemic control in either group. We found higher daytime and nighttime URBP in group B compared to group A ( p < 0.05). We conclude that, in microalbuminuric and low-proteinuric patients, daytime and nighttime BP was elevated but still in the normal or borderline range, and nighttime decrease in BP correlated with nighttime decrease in UAE but not with actual glycemic control. Increased URBP in these patients suggests slightly impaired proximal tubular function in early stages of diabetic nephropathy.

Factors Determining the Blood Pressure Response to Enalapril and Nifedipine in Hypertension Associated With NIDDM

To examine the factors that determine the blood pressure response to enalapril and nifedipine monotherapy in the treatment of hypertension associated with non-insulin-dependent diabetes mellitus (NIDDM). After a 6-week placebo baseline period, 102 hypertensive NIDDM patients were randomly assigned, double-blindly, to treatment with nifedipine retard (slow release) (n = 52) or enalapril (n = 50). The daily dosage of enalapril was increased, if required, from 10 to 20 to 40 mg and that of nifedipine from 40 to 60 to 80 mg at 4-week intervals during the 12-week titration period. Blood pressure, 24-h urinary albumin excretion (UAE), biochemical data, and serum angiotensin-converting enzyme (ACE) activity were measured at weeks -6, -4, 0, 4, 8, and 12. At week 0, venous blood was also sampled for baseline plasma atrial natriuretic peptide, renin, aldosterone, and serum insulin concentrations. At week 12, the mean daily dose of enalapril was 35 +/- 11.4 mg, and 27 (57%) patients were receiving the maximum daily dose of 40 mg. In the nifedipine group, the mean daily drug dose was 50 +/- 12.9 mg, and 4 (8%) were receiving the maximum daily dose of 80 mg. Despite a dose-dependent fall in the serum ACE activity in the enalapril group, the mean arterial pressure (MAP) was reduced by only 8 mmHg throughout the 12-week titration period compared to a decline of 15, 18, and 19 mmHg at weeks 0, 4, and 12, respectively, in the nifedipine group (P = 0.01 between groups). In the enalapril group, changes in MAP between weeks 0 and 12 correlated significantly with baseline plasma glucose (r = 0.45, P = 0.001) and aldosterone concentrations (r = -0.32, P = 0.02) and UAE (r = 0.3, P = 0.04). There was no statistically significant correlation between the changes in MAP and baseline plasma renin concentration. On multivariate analysis, the baseline renal function, glycemic control, and plasma aldosterone and serum insulin concentrations were all independently related to the changes in blood pressure in the enalapril-treated patients. No such statistical associations were observed in the nifedipine group. In hypertensive NIDDM patients, the activity of the renin-angiotensin-aldosterone system, the level of serum insulin, glycemic control, renal function, and proteinuria may be important determinants of the blood pressure response to ACE inhibition. Good glycemic control may optimize the antihypertensive efficacy of concomitant ACE inhibitor therapy.

C18 - Relationship between 24h urinary albumin excretion rate (UAE), left ventricular mass index (LVMI) and 24h ambulatory blood pressure (ABP) in borderline hypertensives (BH) and normotensive offspring of hypertensive parents

C18 - Relationship between 24h urinary albumin excretion rate (UAE), left ventricular mass index (LVMI) and 24h ambulatory blood pressure (ABP) in borderline hypertensives (BH) and normotensive offspring of hypertensive parents

Latent overhydration and nocturnal hypertension in diabetic nephropathy.

With the aim of studying the diurnal variation in blood pressure in relation to degree of fluid retention, 24-h ambulatory blood pressure monitoring was performed in 31 insulin-dependent diabetic patients with nephropathy. The extracellular volume was calculated from the distribution volume of 51Cr-EDTA after a single injection. The study population was arbitrarily divided into two groups, depending on their extracellular volume. Group 1 included 15 patients with a lower extracellular volume and group 2, 16 patients with a higher extracellular volume. Ambulatory blood pressure was measured with a portable monitor using an oscillometric technique. In all patients, the mean +/- SD 24-h ambulatory blood pressure was 135/79 +/- 14/7 mmHg. Day and night-time blood pressure were 136/81 +/- 14/7 and 133/75 +/- 17/8, respectively (p < 0.02). The ambulatory blood pressure was 135/80 +/- 14/7 in group 1 and 136/78 +/- 15/6 mmHg in group 2. The nocturnal change in blood pressure was significantly greater in group 1 than in group 2, -9/-9 +/- 10/5 mmHg and 1/-3 +/- 10/6 mmHg, respectively (p = 0.005/0.01). There were no other significant differences between the groups than the diurnal blood pressure pattern. There were significant correlations between day ambulatory blood pressure and night ambulatory blood pressure and 24-h ambulatory blood pressure and urinary albumin excretion. There was no correlation between ausculatatory clinic blood pressure on the one hand and albuminuria on the other. Latent fluid retention therefore may contribute to nocturnal hypertension in diabetic nephropathy.

Screening Tests for Microalbuminuria in Non-Diabetic Elderly Subjects and Their Relation to Blood Pressure

1. Microalbuminuria in non-diabetic elderly subjects is predictive of vascular disease and mortality, and related to levels of blood pressure. 2. This study was designed to examine whether more restricted periods of urine collection retained the relation to the prevailing level of blood pressure and successfully identified subjects with microalbuminuria. 3. Fifty elderly subjects (aged over 60 years) made two consecutive 24-h urine collections for measurement of urinary albumin excretion, divided between daytime and night-time periods. Thirty-three subjects also provided a random 'spot' urine sample. Clinic and 24-h ambulatory blood pressure were also recorded. 4. Median 24-h urinary albumin excretion was 15.75 mg; 17 subjects had microalbuminuria. The median 24-h albumin-creatinine ratio was 1.91 mg/mmol. A threshold albumin-creatinine ratio of > or = 3.0 mg/mmol in a random urine sample predicted microalbuminuria with 92% sensitivity and 90% specificity. Alternatively, threshold values of 2.5 mg/mmol for men and 4.5 mg/mmol for women in an overnight urine collection predicted microalbuminuria with 88% sensitivity and 100% specificity. 5. The closest relation between albumin-creatinine ratio and blood pressure was that between spot albumin-creatinine ratio and clinic systolic blood pressure (r = 0.64, P < 0.001). Albumin-creatinine ratio was generally related to clinic systolic blood pressure, diastolic blood pressure and ambulatory systolic blood pressure. Microalbuminuric subjects had significantly higher levels of clinic and ambulatory systolic blood pressure than non-microalbuminuric subjects. 6. Microalbuminuria in the elderly is most related to clinic systolic blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Microalbuminuria development in short-term IDDM

To assess risk factors associated with microalbuminuria development in short-term evolution insulin-dependent diabetes mellitus (IDDM) we undertake a cross-sectional study with retrospective examination of the 34 patients diagnosed with IDDM between 1982 and 1983 and followed up for at least 7 years in an outpatient endocrinology clinic. Main measures: (1) At IDDM diagnosis: age, sex, parameters of metabolic control (fasting glycemia, HbA 1), islet-cell antibodies, insulin autoantibodies, endogenous insulin secretion (EIS) and HLA type. (2) At 1 year evolution: EIS re-evaluation. (3) From IDDM diagnosis (every 3–4 month): body mass index, insulin schedule and dose, and parameters of metabolic control. (4) At 7-year evolution: 24-h urinary albumin excretion (UAE) and arterial blood pressure measurements on two consecutive outpatient controls. Microalbuminuria was defined as UAE above 30 μg/min on the two consecutive measurements. After 7-year follow-up, 8 (23.5%; 95% Cl: 9.3 to 37.7%) patients developed microalbuminuria. Their metabolic control was worse (7 years mean HbA 1: 10.7 vs. 9.7%; P = 0.04) and 1 year EIS lower (1.9 vs. 7.6 ng/ml.10 min; P = 0.03) than in normoalbuminuric patients. They also had higher prevalence of ‘high-normal’ arterial blood pressure ( P = 0.03) and diabetic retinopathy ( P = 0.01) than normoalbuminuric patients did. Stepwise logistic regression analysis showed that diabetic retinopathy was the only independent and significant risk factor related to microalbuminuria development ( P = 0.01). We conclude that in subjects with short-term evolution IDDM, microalbuminuria development was associated with glycemic control, EIS and arterial blood pressure levels, however the strongest association was found with diabetic retinopathy occurrence.

Long-Term Glycemic Control and Neurological Function in IDDM Patients

To examine the relationship between sensory modalities of neurological function and antecedent glycemic control in IDDM patients. Examinations were conducted on 220 IDDM patients (age at onset < 25 yr, duration < 18 yr) for the presence or absence of the right or left ankle reflex and determination of vibration perception threshold at each medial malleolus and great toe using biothesiometry. These parameters were related to the concurrent HbA1 and to a mean of serial measurements (mean HbA1) over the previous 6 yr. Ankle reflexes were absent in 39 (right ankle) and 41 (left ankle) patients, respectively. Mean (right + left) ankle and toe VPTs were 8.7 +/- 3.6 and 6.3 +/- 4.2 (mean +/- SD) (arbitrary units), respectively. Both the mean and concurrent HbA1 were significantly different in patients with absent ankle reflexes (11.6 +/- 1.9 and 12.2 +/- 2.8%, respectively) compared with present ankle reflexes (10.3 +/- 1.7, 10.3 +/- 2.1%) (P < 0.0001). Similarly, a present ankle reflex was related to mean HbA1 arbitrarily divided into groups < 10, 10-12, > 12% (P = 0.0009). In contrast, mean ankle VPT (8.0 +/- 2.2, 8.8 +/- 3.1, and 10.3 +/- 6.2) and toe VPT (5.5 +/- 2.2, 6.1 +/- 2.9, and 8.5 +/- 8.2) did not increase significantly with poor glycemic control (P > 0.05). Age, right ankle reflex, retinopathy, 24-h urinary albumin excretion rate, and erect systolic blood pressure were the only independent variables predicting the toe VPT using linear regression analysis. These findings support a role for glycemic control in neurological dysfunction in IDDM patients, but also suggest that other unknown factors may be involved.

Microalbuminuria in Elderly Hypertensives: Variability and Relation to Clinic and Ambulatory Blood Pressure

OBJECTIVE To examine the short-term reproducibility of urinary albumin measurements and the relation of urinary albumin excretion to the clinic and ambulatory blood pressure levels in elderly untreated hypertensive subjects. SETTING Outpatient hypertension clinic of a District General Hospital. MAIN OUTCOME MEASURES The within-patient reproducibility of 24-h urinary microalbumin and electrolyte excretion and relation to 24-h and clinic blood pressure levels. PATIENTS Sixty-four untreated elderly hypertensives (mean age 74.7 years, range 64-82) with systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 95 mmHg, or both, were recruited from general practitioner clinics and current outpatient attenders. The patients had not received antihypertensive treatment for at least 4 weeks. METHODS The clinic and 24-h non-invasive ambulatory blood pressures were recorded with a simultaneous 24-h urine collection for measurement of the urinary albumin and electrolyte excretion. Thirty-seven subjects performed two consecutive 24-h urine collections for an assessment of the short-term reproducibility of the albumin and electrolyte excretion. RESULTS The coefficient of variation of 24-h urinary albumin excretion was 62%, and for the albumin:creatinine ratio 52%, compared with 19% for sodium and 15% for potassium excretion. The urinary albumin excretion correlated with clinic systolic blood pressure (r = 0.33, P = 0.01) and with 24-h ambulatory systolic (r = 0.48, P < 0.001) and diastolic (r = 0.32, P = 0.01) blood pressure. The subjects with microalbuminuria (24-h urinary albumin excretion in the range 30-300 mg) had higher clinic and ambulatory blood pressures than those with lower levels of albumin excretion. CONCLUSIONS The low day-to-day intrasubject reproducibility in the 24-h urinary albumin excretion considerably reduces the potential value of single collections in the assessment of microalbuminuria in elderly hypertensives. The urinary albumin excretion correlates with the clinic and 24-h ambulatory blood pressures in elderly hypertensives.

Dietary Guar Gum Halts Further Renal Enlargement in Rats with Established Diabetes , ,

Guar gum, a dietary fiber known to improve glucose tolerance, was fed to rats with established diabetes to determine its effect on renal enlargement and microalbuminuria. Diabetic rats were fed a modified AIN-76A (basal) diet for 4 wk, at which time half the rats continued to receive the same basal diet (DB-BA group) and half were switched to a 5% guar gum diet (DB-GG group). Nondiabetic rats fed the basal diet served as controls (NRL group). After 8 additional weeks the animals were killed. Glycated hemoglobin, a measure of long-term blood glucose control, was 14.4% in the DB-BA group and 12.4% in the DB-GG group, a statistically significant difference (P < 0.05). Kidney weight of the DB-BA group (3.51 g) was significantly greater than that of the DB-GG group (2.76 g) (P < 0.05). Eight weeks after induction of diabetes, 24-h urinary albumin excretion was highest in the DB-BA group and lowest in the NRL group; excretion in the DB-GG group (4 wk of guar feeding) was intermediate. However, by 12 wk no differences in albumin excretion among the groups were apparent. These results suggest that guar gum may be useful for slowing the progression of diabetic nephropathy and that guar gum deserves further study in this regard.

12 Microalbuminuria in elderly hypertensives: variability and relation to clinic and ambulatory blood pressure

To examine the short-term reproducibility of urinary albumin measurements and the relation of urinary albumin excretion to the clinic and ambulatory blood pressure levels in elderly untreated hypertensive subjects. Outpatient hypertension clinic of a District General Hospital. The within-patient reproducibility of 24-h urinary microalbumin and electrolyte excretion and relation to 24-h and clinic blood pressure levels. Sixty-four untreated elderly hypertensives (mean age 74.7 years, range 64-82) with systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 95 mmHg, or both, were recruited from general practitioner clinics and current outpatient attenders. The patients had not received antihypertensive treatment for at least 4 weeks. The clinic and 24-h non-invasive ambulatory blood pressures were recorded with a simultaneous 24-h urine collection for measurement of the urinary albumin and electrolyte excretion. Thirty-seven subjects performed two consecutive 24-h urine collections for an assessment of the short-term reproducibility of the albumin and electrolyte excretion. The coefficient of variation of 24-h urinary albumin excretion was 62%, and for the albumin:creatinine ratio 52%, compared with 19% for sodium and 15% for potassium excretion. The urinary albumin excretion correlated with clinic systolic blood pressure (r = 0.33, P = 0.01) and with 24-h ambulatory systolic (r = 0.48, P < 0.001) and diastolic (r = 0.32, P = 0.01) blood pressure. The subjects with microalbuminuria (24-h urinary albumin excretion in the range 30-300 mg) had higher clinic and ambulatory blood pressures than those with lower levels of albumin excretion. The low day-to-day intrasubject reproducibility in the 24-h urinary albumin excretion considerably reduces the potential value of single collections in the assessment of microalbuminuria in elderly hypertensives. The urinary albumin excretion correlates with the clinic and 24-h ambulatory blood pressures in elderly hypertensives.