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H H Parving

Publications and source records attributed to H H Parving.

At least 109 records · Page 6Linked to original sources
PubMed1997

Lisinopril improves endothelial dysfunction in hypertensive NIDDM subjects with diabetic nephropathy.

Endothelial dysfunction is a prevalent phenomenon in non-insulin dependent diabetic (NIDDM) patients with hypertension and albuminuria, and may contribute to the development and progression of cardiovascular disease, which is the main cause of the high morbidity and mortality observed in these patients. Therefore the aim of our study was to evaluate whether inhibition of angiotensin-converting enzyme (with lisinopril 10-20 mg day-1) could ameliorate endothelial dysfunction more than reducing blood pressure with conventional antihypertensive treatment (atenolol 50-100 mg day-1), usually in combination with a diuretic. We performed a 12-month prospective, randomized, double-blind, parallel study in 43 hypertensive NIDDM patients with diabetic nephropathy (21 treated with lisinopril and 22 with atenolol). The following variables were measured: 24-h ambulatory blood pressure (ABP); transcapillary escape rate of albumin (TERalb; i.e. initial disappearance of intravenously injected 125I-labelled human serum albumin); serum concentrations of von Willebrand factor (vWF), using ELISA, and urinary albumin excretion rate (UAE). Data are presented for 32 patients (16 lisinopril and 16 atenolol; age 60 years, SD 8; 25 males) out of 35 who completed the study and had valid measurements of TERalb. At baseline the two groups were comparable; TERalb (8.5 (SEM 0.6) vs. 7.2 (0.4)%); vWF (2.09 (range 0.82-4.34) vs. 1.97 (0.95-3.86) IU ml-1; UAE 916 (x/divided by antilog SEM 1.3) vs. 1444 (1.2), and mean ABP 110 (SEM 3) vs. 113 (2) mmHg, in the lisinopril and atenolol group, respectively. During follow up, the mean ABP was equally reduced in the lisinopril and atenolol group, by 12 (SEM 2) vs. 10 (2) mmHg, respectively, TERalb decreased in the lisinopril group by 0.6 (SEM 0.7)%, whereas it increased in the atenolol group 1.5 (0.5)%; the mean difference was 2.2% (95% CI, 0.5 to 3.9; p = 0.015). UAE was reduced by 45% (95% CI, 25 to 60) in the lisinopril group vs. 10% (-15 to 30) in the atenolol group (p = 0.014). Serum vWF was not changed during follow up in either group. Our study suggests that lisinopril has both reno- and vasculoprotective properties in hypertensive NIDDM patients with diabetic nephropathy.

Aged↗
PubMed1997

Kidney function after withdrawal of long-term antihypertensive treatment in diabetic nephropathy.

Initiation of antihypertensive treatment in hypertensive non-insulin-dependent diabetic (NIDDM) patients with diabetic nephropathy induces a faster initial (0 to 6 months) and slower subsequent (6 months-end) decline in GFR [delta GFR (ml.min-1.1.73 m-2.month-1) approximately 1.5 vs. 0.4]. Whether this initial phenomenon is reversible (hemodynamic) or irreversible (structural damage) after prolonged antihypertensive treatment is not known. To elucidate these mechanisms we investigated 40 hypertensive NIDDM patients (age 61 +/- 7 years, mean +/- SD), known duration of diabetes 14 years (2 to 33 years) [median (range)] with diabetic nephropathy receiving antihypertensive treatment (angiotensin converting enzyme inhibition, N = 30) for 5 years (1 to 20 years). The following variables were measured the last day on antihypertensive treatment and one month after withdrawal of treatment; GFR (51Cr-EDTA), 24-hour arterial blood pressure (24 hr MABP, Takeda TM2420) and albuminuria (ELISA); the mean 24-hour MABP rose from 102 +/- 11 to 111 +/- 10 (P < 0.0001) and albuminuria [geometric mean (antilog SEM)] increased from 634 (1.3) to 1159 (1.2) (P < 0.0001), while GFR (mean +/- SD) remained unchanged (69 +/- 25 to 70 +/- 26 ml.min-1.1.73 m-2, P = 0.21), after withdrawal of antihypertensive treatment. A significant correlation between the relative change in the 24 hour MABP measurement and the relative change in GFR (r = 0.44, P < 0.01) was found. In conclusion, our results suggest that the faster initial decline in GFR after initiating antihypertensive treatment in hypertensive NIDDM patients with diabetic nephropathy is due to a irreversible effect, and should be accounted for when evaluating the beneficial effect of antihypertensive treatment on the progression of diabetic nephropathy in these patients.

Adolescent↗
PubMed1997

Surrogate endpoints and renal protection: focus on microalbuminuria.

End-stage renal disease (ESRD) is a major public health problem worldwide. The past decade has witnessed increased interest and investigative attention on therapeutic manoeuvres to retard the progression of renal disease. Reduction of albuminuria is regarded as a surrogate endpoint, because this phenomenon seems to be associated with preservation of GFR (principal endpoint) in diabetic nephropathy. Studies from our laboratory suggest that reduction in albuminuria during ACE inhibition constitutes a predictor of an attenuated rate of decline in GFR in early diabetic nephropathy. Because the rate of decline in kidney function is used to assess prognosis and the efficacy of therapy on progression of renal disease, a valid method for the determination of GFR is essential. During the last two decades, several radioactive and non-radioactive filtration markers have been validated and found to be both accurate and precise compared to inulin. Plasma clearance of such filtration markers is frequently applied in clinical trials in diabetic nephropathy because patients suffering from this complication frequently also suffer from diabetic cystopathy, precluding measurements of urine volume. Measurements of serum creatinine, creatinine clearance, calculated creatinine clearance by use of the Cockroft-Gault formula must all be regarded as surrogate measurements for glomerular filtration rate. Consequently, care must be taken to select appropriate filtration markers in order to rigorously evaluate therapeutic trials in progressive renal disease.

Albuminuria↗
PubMed1996

[Low birth weight--increased risk of diabetic nephropathies?].

It has been demonstrated that intrauterine growth retardation gives rise to a reduction in nephron number. Oligonephropathy has been suggested to enhance the risk for expression of renal disease following exposure to potentially injurious renal stimuli. In a case-control study we investigated if low birth weight is a risk factor for development of diabetic nephropathy in 184 IDDM patients with diabetic nephropathy (persistent albuminuria > 300 mg/24 hours) and 182 normoalbuminuric (< 30 mg/24 hours) patients. In women with birthweight < 10 th centile (< or = 2,700 g, n = 16) 75% had nephropathy compared to only 35% among patients > 90 th centile (> or = 4,000 g, n = 17) (p = 0.05). In men with birth-weight < 10th centile (< or = 2,910 g, n = 22) the prevalence of nephropathy: 50%, was similar to the prevalence among patients > 90th centile (> or = 4,200 g, n = 24) 54%. Mean weight at birth were similar in patients with and without diabetic nephropathy. Men with diabetic nephropathy were significantly shorter than men with normoalbuminuria (176.9 (7.1) vs 179.4 (6.5), p < 0.01). In conclusion, our study supports the hypothesis that genetic predisposition or factors operating in utero or early childhood, or both, contribute to the development of diabetic nephropathy.

Adult↗
PubMed1996

[Albuminuria and glycemic control. The significance for mortality in non-insulin-dependent diabetes mellitus].

The impact of microalbuminuria and macroalbuminuria on mortality was evaluated prospectively in 328 Caucasian patients with non-insulin-dependent diabetes mellitus (NIDDM) followed for five years. One hundred and ninety-one patients with normoalbuminuria (albumin excretion rate (AER) < 30 mg/24 h), 86 patients with microalbuminuria (AER 30-299 mg/24 h), and 51 patients with macroalbuminuria (AER > or = 300 mg/24 h) all less than 66 years old at start of the study were followed from 1987 until death or until 1 January 1993. Eight percent of patients with normoalbuminuria, 20% of patients with microalbuminuria, and 35% of patients with macroalbuminuria had died, predominantly from cardiovascular disease. Significant predictors of all-cause mortality included preexisting coronary heart disease, AER, HbA1c level and age. Significant predictors of cardiovascular mortality included preexisting coronary heart disease, macroalbuminuria, HbA1c level and systolic blood pressure. Abnormally elevated urinary albumin excretion and poor glycaemic control indicate a substantially increased all-cause, mainly cardiovascular, mortality risk in NIDDM patients.

Adult↗
PubMed1996

[Diabetic nephropathy. Unchanged occurrence in patients with insulin-dependent diabetes mellitus].

Recently, a dramatic decline in the cumulative incidence of diabetic nephropathy (less than 10% after 25 years of diabetes) has been reported in IDDM patients diagnosed between 1961 and 1980. In a clinic based study we assessed recent trends in the incidence of diabetic nephropathy. All 356 patients in whom IDDM was diagnosed before the age of 41 years between 1965 and 1979, identified in 1984 were followed to 1991 or to death. The cumulative incidence of diabetic nephropathy (urinary albumin excretion 300 mg/24 hours in two out of three consecutive samples) after 15 years of diabetes and in 1991 were (cumulative incidence (SE)): 18 (4)% and 35 (5)% (onset of diabetes 1965-69, n = 113), 20 (4)% and 35 (5)% (onset of diabetes 1970-74, n = 130), and 16 (5)% (onset of diabetes 1975-79, n = 113), respectively (ns). The mean (SE) haemoglobin A1c measured yearly beginning in 1984 was higher in patients with nephropathy (9.4 (0.1)%), and persistent microalbuminuria (8.9 (0.1)%) than in patients with normoalbuminuria (8.5 (0.1)%, (p < 0.001)). Our study revealed no decline in the cumulative incidence of diabetic nephropathy with increasing calendar year of diabetes onset. This may in part be explained by poor metabolic control and a high prevalence of smokers (58-71%).

Adolescent↗
PubMed1996

Predictors of mortality in insulin dependent diabetes: 10 year observational follow up study.

OBJECTIVE: To evaluate the prognostic significance of microalbuminuria and overt diabetic nephropathy and other putative risk factors for cardiovascular and all cause mortality in insulin dependent diabetes. DESIGN: Ten year observational follow up study. SETTING: Outpatient diabetic clinic in a tertiary referral centre. SUBJECTS: All 939 adults with insulin dependent diabetes (duration of diabetes five years or more) attending the clinic in 1984; 593 had normal urinary albumin excretion (< or = 30 mg/24 h), 181 persistent microalbuminuria (31-299 mg/24 h), and 165 overt nephropathy (> or = 300 mg/24 h). MAIN OUTCOME MEASURE: All cause and cardiovascular mortality. RESULTS: Fifteen per cent of patients (90/593) with normoalbuminuria, 25% (45/181) with microalbuminuria, and 44% (72/165) with overt nephropathy at baseline died during follow up. Cox multiple regression analysis identified the following significant predictors of all cause mortality: male sex (relative risk 2.03; 95% confidence interval 1.37 to 3.02), age (1.07; 1.06 to 1.08), height (0.96; 0.94 to 0.98), smoking (1.51; 1.09 to 2.08), social class V versus social class IV (1.70; 1.25 to 2.31), log10 urinary albumin excretion (1.45; 1.18 to 1.77), hypertension (1.63; 1.18 to 2.25), log10 serum creatinine concentration (8.96; 3.34 to 24.08), and haemoglobin A1c concentration (1.11; 1.03 to 1.20). Age, smoking, microalbuminuria, overt nephropathy, and hypertension were significant predictors of cardiovascular mortality. Mortality in patients with microalbuminuria was only slightly increased compared with that in patients with normoalbuminuria. Median survival time after the onset of overt diabetic nephropathy was 13.9 years (95% confidence interval 11.8 to 17.2 years). CONCLUSIONS: Abnormally increased urinary albumin excretion and other potentially modifiable risk factors such as hypertension, smoking, poor glycaemic control, and social class predict increased mortality in insulin dependent diabetes. Microalbuminuria by itself confers only a small increase in mortality. The prognosis of patients with overt diabetic nephropathy has improved, probably owing to effective antihypertensive treatment.

Adult↗
PubMed1996

Effect of deletion polymorphism of angiotensin converting enzyme gene on progression of diabetic nephropathy during inhibition of angiotensin converting enzyme: observational follow up study.

OBJECTIVE: To evaluate the concept that an insertion/deletion polymorphism of the angiotensin converting enzyme gene predicts the therapeutic efficacy of inhibition of angiotensin converting enzyme on progression of diabetic nephropathy. DESIGN: Observational follow up study of patients with insulin dependent diabetes and nephropathy who had been treated with captopril for a median of 7 years (range 3-9 years). SETTING: Outpatient diabetic clinic in a tertiary referral centre. PATIENTS: 35 patients with insulin dependent diabetes and nephropathy were investigated during captopril treatment (median 75 mg/day (range 12.5 to 150 mg/day)) that was in many cases combined with a loop diuretic, 11 patients were homozygous for the deletion allele and 24 were heterozygous or homozygous for the insertion allele of the angiotensin converting enzyme gene. MAIN OUTCOME MEASURES: Albuminuria, arterial blood pressure, and glomerular filtration rate according to insertion/deletion polymorphism. RESULTS: The two groups had comparable glomerular filtration rate, albuminuria, blood pressure, and haemoglobin A1c concentration at baseline. Captopril induced nearly the same reduction in mean blood pressure in the two groups-to 103 (SD 5) mm Hg in the group with the deletion and 102 (8) mm Hg in the group with the insertion-and in geometric mean albumin excretion-573 (antilog SE 1.3) micrograms/min and 470 (1.2) micrograms/min, respectively. The rate of decline in glomerular filtration rate (linear regression of all glomerular filtration rate measurements during antihypertensive treatment) was significantly steeper in the group homozygous for the double deletion allele than in the other group (mean 5.7 (3.7) ml/min/year and 2.6 (2.8) ml/min/year, respectively; P = 0.01). Multiple linear regression analysis showed that haemoglobin A1c concentration, albuminuria, and the double deletion genotype independently influenced the sustained rate of decline in glomerular filtration rate (R1 (adjusted) = 0.51). CONCLUSION: The deletion polymorphism in the angiotensin converting enzyme gene reduces the long term beneficial effect of angiotensin converting enzyme inhibition on the progression of diabetic nephropathy in patients with insulin dependent diabetes.

Adult↗
PubMed1996

Glomerular hyperfiltration in microalbuminuric NIDDM patients.

Glomerular hyperfiltration and microalbuminuria are both regarded as risk factors for the development of diabetic nephropathy in insulin-dependent diabetic patients. Information on glomerular hyperfiltration is scarce in microalbuminuric non-insulin-dependent diabetic (NIDDM) patients. Therefore, we performed a cross-sectional study of glomerular filtration rate (single i.v. bolus injection of 51Cr-EDTA, plasma clearance for 4 h) in 158 microalbuminuric NIDDM patients compared to 39 normoalbuminuric NIDDM patients and 20 non-diabetic control subjects. The groups were well-matched with regard to sex, age and body mass index. The uncorrected (ml/min) and the adjusted (ml. min-1. 1.73 m-2) glomerular filtration rate were both clearly elevated in the microalbuminuric patients: 139 +/- 29 and 117 +/- 24 as compared to 115 +/- 19 and 99 +/- 15; 111 +/- 23 and 98 +/- 21 in normoalbuminuric NIDDM patients and control subjects, respectively (p < 0.001). The glomerular filtration rate (ml. min-1. 1.73 m-2) in NIDDM patients who had never received antihypertensive treatment was also clearly elevated in the microalbuminuric patients (n = 96): 119 +/- 22 as compared to 100 +/- 14 and 98 +/- 21 in normoalbuminuric NIDDM patients (n = 27) and control subjects (n = 20), respectively (p < 0.001). Glomerular hyperfiltration (elevation above mean glomerular filtration rate plus 2 SD in normoalbuminuric NIDDM patients) was demonstrated in 37 (95% confidence interval 30-45)% of the microalbuminuric patients. Multiple regression analysis revealed that HbA1c, 24-h urinary sodium excretion, age and known duration of diabetes were correlated with glomerular filtration rate in microalbuminuric NIDDM patients (r2 = 0.21, p < 0.01). Our cross-sectional study indicates that NIDDM patients at high risk of developing diabetic nephropathy are also characterized by an additional putative risk factor for progression, glomerular hyperfiltration.

Aged↗
PubMed1996

Macro-microangiopathy and endothelial dysfunction in NIDDM patients with and without diabetic nephropathy.

The Steno hypothesis suggests that albuminuria reflects widespread vascular damage (proliferative retinopathy and severe macroangiopathy) due to a generalized vascular (endothelial) dysfunction. We assessed this concept in NIDDM (non-insulin-dependent diabetic) patients with (13 female/ 39 male, age 60 +/- 7 years, group 1) and without (12 female /41 male, age 61 +/- 7 years, group 2) diabetic nephropathy compared to matched non-diabetic subjects (7 female/15 male, age 58 +/- 8 years, group 3). A 12-lead ECG was recorded and coded blindly using the Minnesota Rating Scale; the World Health Organization cardiovascular questionnaire was used to assess past and present evidence of myocardial infarction, angina pectoris, stroke, and peripheral vascular disease (digital systolic blood pressure determination). The degree of diabetic retinopathy was scored from fundus photography. The following variables were measured: transcapillary escape rate of albumin (initial disappearance of intravenously injected 125I-labelled human serum albumin), plasma concentrations of prorenin (radioimmunoassay) and serum concentrations of von Willebrand factor (enzyme-linked immunoadsorbent assay). Prevalence of ischaemic heart disease (ECG reading) (49/20/5)% and peripheral vascular disease as indicated by reduced systolic blood pressure on big toe (69/30/ 14)% was significantly higher in group 1 vs group 2 (p < 0.01) and in group 2 vs group 3 (p < 0.01), respectively. The prevalence and severity of retinopathy was higher in group 1 vs 2 (p < 0.01). Transcapillary escape rate of albumin (%/h) was elevated in group 1 and 2 as compared to control subjects: 7.9 (4.3-13.7); 7.4 (3.7-16.4) vs 6.0 (3.4-8.7), (p < 0.005), respectively. Plasma prorenin activity (IU/ml) was raised in group 1 and group 2 as compared to group 3: 272 (59-2405); 192 (18-813), and 85 (28-246), p < 0.001, respectively. Serum von Willebrand factor (IU/ ml) was elevated in group 1 as compared to group 2 and 3: 2.07 (0.83-4.34); 1.60 (0.30-2.99) and 1.50 (1.00-2.38), p < 0.001, respectively. Our study demonstrated that NIDDM patients with and without albuminuria had increased transcapillary escape of albumin and raised prorenin activity, whereas only those with albuminuria had increased von Willebrand factor. Patients with NIDDM may have abnormal endothelial function in the absence of albuminuria.

Aged↗
PubMed1996

Benefits of long-term antihypertensive treatment on prognosis in diabetic nephropathy.

We assessed the prognosis of diabetic nephropathy during long-term antihypertensive treatment as compared to the prognosis during the natural history of this complication in a prospective study of all IDDM patients (N = 45) aged under 50 with onset of diabetes before the age of 31 who developed diabetic nephropathy between 1974 and 1978 at Steno Diabetes Center, and were followed until death or for at least 16 years [median 16 (4 to 21) years]. Antihypertensive treatment was started 3 (0 to 13) years after onset of diabetic nephropathy. Mean arterial blood pressure at start of antihypertensive treatment was 148/96 (sd 12/10) mm Hg and 143/86 (16/6) mm Hg during the whole interval of antihypertensive treatment (P < 0.01). The cumulative death rate was 45% (95% C.I. 38 to 52) 16 years after onset of diabetic nephropathy, in contrast to previous reports 88% and 94% 12 and 16 years after onset of diabetic nephropathy, respectively. The median survival time in our study exceeded 16 years as compared to five and seven years in untreated patients in the past. Uremia was the main cause of death (12 patients; 55%). In 1994 serum creatinine was 116 (74 to 311) mumol/liter in the 23 surviving patients. The preservation of kidney function and the prognosis of diabetic nephropathy has improved during the past two decades mainly because of effective antihypertensive treatment.

Adult↗
PubMed1996

Circadian rhythm of arterial blood pressure and albuminuria in diabetic nephropathy.

The aim of our study was to evaluate the diurnal relationship between arterial blood pressure and albuminuria, and some potential mechanisms responsible for impaired nocturnal blood pressure reduction (non-dippers, groups I and II) in diabetic nephropathy (DN). Twenty-four-hour ambulatory blood pressure, heart rate (HR) variation (autonomic nervous function) and extracellular fluid volume (ECV) were measured, and urine samples were collected three times during the corresponding day- and nighttimes in 47 insulin-dependent diabetic (IDDM) patients with DN. Mean arterial blood pressure (MABP) during the daytime [mm Hg, median (range)] was identical in group I [105 (96-137)], group II [109 (86-124)] and group III [dippers; average blood pressure reduction from day to night > 10%, 107 (93-132), P = NS], while the nighttime MABP differed [group I, 106 (95-144); group II, 100 (78-118); group III, 91 (76-118); P < 0.001]. No significant difference between the groups concerning the daytime or nighttime albuminuria [microgram/min; median (range)] was observed; [Day: group I, 1467 (235-3933); group II, 695 (170-6719); group III, 875 (228-3173). Night: group I, 1079 (279-4665); group II, 572 (113-3807); group III, 659 (81-2493)]. A significant correlation between MABP and albuminuria was demonstrated during day- (rho = 0.50, P < 0.0005) and nighttime (rho = 0.46, P < 0.005), while neither the absolute nor the relative changes in MABP from day to night correlated significantly with absolute or relative changes in albuminuria from day to night. The night/day ratio of HR was higher in group I [0.93 (0.76-1.09), median (range)] compared to group III [0.83 (0.74-1.02), P < 0.005] and a significant correlation between this ratio and the night/day ratio of MABP was found (rho = 0.54, P < 0.0005). ECV was about the same in the three groups. Our study indicated an association between blood pressure and albuminuria, but the mechanisms involved in the reduction of albuminuria from day to night was not unraveled. A relative lack of sympathetic withdrawal during sleep seems to be an important feature of nocturnal hypertension in diabetic nephropathy.

Adult↗
PubMed1996

Renal protection in diabetes: an emerging role for calcium antagonists.

BACKGROUND: The combination of diabetes and hypertension increases the chances of progressive renal disorder and, ultimately, renal failure. Roughly 40% of all diabetics, whether insulin-dependent or not, develop diabetic nephropathy. Diabetic nephropathy is the single most important cause of end-stage renal disease in the Western world and accounts for more than a quarter of all end-stage renal diseases. Diabetic nephropathy is a major cause of increased morbidity and mortality in diabetic patients. Increased arterial blood pressure is an early and common phenomenon in incipient and overt diabetic nephropathy. The relationship between arterial blood pressure and diabetic nephropathy is a complex one, with diabetic nephropathy increasing blood pressure and blood pressure accelerating the course of nephropathy. OVERVIEW: Calcium antagonists antagonize preglomerular vasoconstriction. Additional putative mechanisms include the ability to retard renal growth and possibly to attenuate mesangial entrapment of macromolecules, and to attenuate the mitogenic effect of diverse growth factors. Calcium antagonists (except the original short-acting dihydropyridine drugs) reduce microalbuminuria and preserve kidney function in diabetic patients with incipient diabetic nephropathy. There are still no long-term trials using the new long-acting dihydropyridine calcium antagonists to treat patients with incipient nephropathy. A recent, 1-year, randomized, double-blind study in hypertensive insulin-dependent diabetic patients with diabetic nephropathy showed a better attenuation of the rate of decline in glomerular filtration in patients treated with nisoldipine (long-acting dihydropyridine) than with an angiotension converting enzyme (ACE) inhibitor. The mean 24-h arterial blood pressure during this study was almost identical in both treatment groups, at 103 (SD 9) and 101 (SD 11) mmHg, respectively. Furthermore, a recent 5-year randomized open study in hypertensive non-insulin-dependent patients with diabetic nephropathy has revealed the same beneficial effect of a calcium antagonist and of ACE inhibition on the progression of nephropathy. In a third group treated with sympatholytic drugs, creatinine levels doubled in more than 50% of the subjects compared to less than 10% in the two other groups mentioned above. However, long-term studies are needed to consolidate these findings and expand them to insulin-dependent diabetic patients with diabetic kidney disease.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1996

Microalbuminuria in essential hypertension and diabetes mellitus.

DEFINITION: Microalbuminuria is defined as abnormally elevated urinary albumin excretion below the level of clinical albuminuria (albustix). This represents a urinary albumin excretion rate of 20-200 micrograms/min, equal to 30-300 mg/24 h. Urinary albumin excretion can vary as much as 40% with natural fluctuations, and so several tests should be done. Inexpensive radioimmunoassay, enzyme-linked immunosorbent assays or immunoturbidimetric assays are now routine in many clinical laboratories. PREVALENCE: The prevalence of microalbuminuria in essential hypertension and diabetes is about the same: 25% (range 14-31) and 20% (9-27), respectively. MECHANISMS: Increased transglomerular passage is the major mechanism of microalbuminuria in both the above-mentioned conditions; increased hydraulic glomerular capillary pressure and glomerular lesions probably both contribute. Microalbuminuria is highly predictive of the development of diabetic nephropathy but the predictive power in relation to hypertensive nephropathy remains to be established. However, in both conditions microalbuminuria is associated with an increased risk of retinopathy, left ventricular hypertrophy, fatal and non-fatal cardiovascular disease and all-cause mortality. The following mechanisms have been suggested as a link between microalbuminuria and these findings: endothelial dysfunction, insulin resistance, hyperinsulinemia, dyslipoproteinemia and a procoagulant state. EFFECT OF ANTIHYPERTENSIVE TREATMENT: Blood pressure lowering reduces microalbuminuria in essential hypertension and in diabetes mellitus. Long-term studies in diabetes suggest that angiotensin converting enzyme inhibitors postpone, and may even prevent, progression to overt clinical nephropathy in normotensive diabetic patients with persistent microalbuminuria. So far, there have been no long-term comparative trials on the beneficial effects of different antihypertensive drugs in hypertensive patients with microalbuminuria.

Albuminuria↗
PubMed1996

Genetics of diabetic nephropathy.

Diabetic nephropathy is a clinical syndrome characterized by persistent albuminuria, a relentless decline in GFR, raised arterial blood pressure, and increased relative mortality for cardiovascular diseases. Diabetic nephropathy is a leading cause of end-stage renal failure. The pathogenesis of diabetic nephropathy is multifactorial, with contributions from metabolic abnormalities, hemodynamic alterations, and various growth factors and genetic factors. Epidemiologic and family studies have demonstrated that only a subset of the patients develop this complication that family clustering of nephropathy is present, and that ethnicity plays an important role in the risk of developing this kidney disease. Short stature and low birth weight are both associated with increased risk of developing diabetic nephropathy, supporting the hypothesis that genetic predisposition or factors operating in utero, in early childhood, or both contribute to the development of diabetic nephropathy. Studies elucidating phenotypic markers such as parenteral hypertension and systemic blood pressure elevation have yielded conflicting results. The contribution from elevated blood pressure only plays a minor role in the majority of the patients developing diabetic nephropathy. The majority of the studies have demonstrated increased sodium/lithium countertransport activity in insulin-dependent diabetes mellitus patients with nephropathy, whereas studies of this phenotypic marker in parents of patients with and without nephropathy have yielded conflicting results. Recently, studies of genetic markers involved in the regulation of blood pressure and levels of cardiovascular risk factors have been conducted. Several studies have demonstrated that the deletion polymorphism in the angiotensin-I-converting enzyme acts as a risk factor for cardiovascular disease in diabetic patients. However, a meta-analysis does not support the suggestion that this factor plays any role for the initiation of diabetic nephropathy. Similar negative results have been obtained in relation to polymorphisms of the genes encoding for angiotensinogen and the angiotensin II Type 1 receptor. However, studies in diabetic and non-diabetic glomerulopathies have clearly demonstrated a deleterious effect of the deletion polymorphism in the angiotensin-converting enzyme on the progression of kidney function.

Antiporters↗
PubMed1996

Angiotensinogen gene polymorphisms in IDDM patients with diabetic nephropathy.

Genotypic abnormalities of the renin-ANG system have been suggested as a risk factor for the development of diabetic nephropathy. Cleavage of angiotensinogen is the rate-limiting step in the activation of the renin-ANG system. The TT genotype of a polymorphism encoding threonine instead of methionine (M235T) has been associated not only with increased plasma angiotensinogen concentration but also with essential hypertension. In addition, a polymorphism in the angiotensinogen gene substituting methionine for threonine (T174M) has been associated with hypertension in nondiabetic populations. We studied the relationship between these polymorphisms in the angiotensinogen gene in IDDM patients with diabetic nephropathy (121 men, 74 women, age 40.9 +/- 10 years, diabetes duration 27 +/- 8 years). There was no difference in M235T genotype distribution between IDDM patients with diabetic nephropathy and those with normoalbuminuria: 73/97/25 (37/50/13%) vs. 67/95/23 (36/52/12%) had MM/MT/TT genotypes, respectively. No difference in distribution of T174M genotypes between nephropathic and normoalbuminuric IDDM patients was observed either: 148/44/1 (77/23/0.5%) vs. 141/42/2 (76/23/1%) had TT/TM/MM genotypes, respectively. In patients with nephropathy, systolic blood pressure was higher (161 +/- 22 mmHg [mean +/- SD]) in patients carrying TT genotype of the M235T angiotensinogen polymorphism as compared with patients with MM or MT genotypes (150 +/- 23 mmHg; P = 0.03). We conclude that neither the M235T nor the T174M polymorphism in the angiotensinogen gene contributes to genetic susceptibility to diabetic nephropathy in white IDDM patients, whereas the TT genotype of the M235T is associated with elevated blood pressure in patients with diabetic nephropathy.

Adult↗