Ambulatory blood pressure in type 2 diabetic patients with albuminuria: relation to the renal function and structural lesions

The effect of achieving a systolic blood pressure of 140 mmHg. A prospective study of ambulatory measurements in type 2 diabetic patients with nephropathy

OBJECTIVES

What is the prognostic significance of achieving a systolic blood pressure of <140 mmHg?

SETTING

Diabetic renal policlinic, university hospital of Lund, Sweden.

SUBJECTS

118 type 2 diabetic patients with micro-macroalbuminuria were followed for four years (range 1-8 years). METHOD AND MAIN OUTCOME MEASURES: The prognostic significance of office, day- and nighttime measurements of blood pressure (BP) for development of cardiovascular complications was studied.

RESULTS

Forty-two percent (n=49) developed one or more of the following cardiovascular endpoints: 23% (n=27) death, 9% (n=10) stroke, 9% (n=11) myocardial infarction, 9% (n=11) heart failure, 31% (n=36) uremia and 17% (n=20) need for dialysis. Reaching the goal for day- and nighttime systolic BP (SBP) at baseline of <140 mmHg was associated with lower risk for developing uremia. Reaching the goal for nighttime SBP was associated with a decreased risk for developing myocardial infarction and need for dialysis treatment. None of these associations was found for office SBP. Patients not achieving the goal for nighttime systolic blood pressure of <140 mmHg had a 12.9 times higher risk of developing myocardial infarction and 3.9 times increased risk of uremia and 2.7 times increased risk for death than patients achieving the goal.

CONCLUSION

Nighttime blood pressure had better prognostic significance for developing cardiovascular and renal complications than office and daytime blood pressure.

The response to antihypertensive therapy is dependent on renal structural changes. A 5-year prospective study of renal biopsy in type 2 diabetic patients with micro-macroalbuminuria

A substantial fraction of patients with diabetes mellitus develop end-stage renal disease. We wanted to study the influence of renal structural changes on the response to treatment of the systemic blood pressure (BP) in type 2 diabetic patients with micro- or macroalbuminuria.

METHODS

A 5-year observational prospective study of 40 type 2 diabetic patients. Renal biopsy was performed on the indication micro-macroalbuminuria. Twenty-four-hour ambulatory BP and urine sampling were performed yearly. The goal for treatment was a nightly systolic BP below 140 mmHg. Glomerular filtration rate was examined early with plasma clearance of iohexol.

RESULTS

The nightly systolic BP goal <140 mmHg was achieved in 23 of 40 patients. The nightly systolic BP at start of study was correlated to the mean level of nightly systolic BP during the observation period. The glomerular basement membrane (GBM) thickness (BMT) was of prognostic significance for achieving the goal for antihypertensive treatment. Of the 12 patients with BMT below the median of 478 nm, 9 (75%) achieved the goal, while only 5 of 12 (42%) with BMT above 478 nm achieved a nightly systolic BP <140 mmHg. Also, the degree of interstitial fibrosis correlated to the nightly systolic BP.

CONCLUSION

A thick basement membrane and the degree of interstitial fibrosis were associated with a lower number of patients achieving the goal of a nightly systolic BP <140 mmHg.

Decreased urinary concentration of Tamm-Horsfall protein is associated with development of renal failure and cardiovascular death within 20 years in type 1 but not in type 2 diabetic patients

OBJECTIVE

The first changes in the diabetic kidney are glycogen deposits in the epithelial cells of the thick ascending limb of Henle. These cells produce Tamm-Horsfall protein (THP). Is low excretion of THP associated with the development of renal insufficiency or cardiovascular disease?

MATERIAL AND METHODS

Urine samples were collected at baseline in patients with type 1 (n = 131) and type 2 (n = 108) diabetes who were followed for a mean of 14 years (range 1-20 years) and 4.5 years (range 1-15 years), respectively.

RESULTS

Twenty percent of type 1 and 54% of type 2 diabetic patients died and 24% and 29%, respectively developed uraemia. A decreased urinary concentration of THP (u-THP) was associated with an eight-fold increased risk of renal failure and cardiovascular death in type 1 but not in type 2 diabetic patients, irrespective of the degree of albuminuria and glycosylated haemoglobin and blood pressure levels. There were no differences in the degrees of albuminuria, serum creatinine or u-THP between the two types of diabetic patients at baseline. Low u-THP occurred in 8% and 9% of normoalbuminuric type 1 and type 2 diabetic patients, respectively.

CONCLUSION

A decreased u-THP was associated with an eight-fold increased risk of cardiovascular death and uraemia in type 1 but not in type 2 diabetic patients.

Ambulatory blood pressure is a better marker than clinic blood pressure in predicting cardiovascular events in patients with/without type 2 diabetes

BACKGROUND

The prognostic significance of ambulatory blood pressure (ABP) has not been established in patients with type 2 diabetes (T2DM).

METHODS

In order to clarify the impact of ABP on cardiovascular prognosis in patients with or without T2DM, we performed ABP monitoring (ABPM) in 1,268 subjects recruited from nine sites in Japan, who were being evaluated for hypertension. The mean age of the patients was 70.4 +/- 9.9 years, and 301 of them had diabetes. The patients were followed up for 50 +/- 23 months. We investigated the relation between incidence of cardiovascular diseases (CVDs) and different measures of ABP, including three categories of awake systolic blood pressure (SBP <135, 135-150, and >150 mm Hg), sleep SBP (<120, 120-135, and >135 mm Hg), and dipping trends in nocturnal blood pressure (BP) (dippers, nondippers, and risers). Cox regression models were used in order to control for classic risk factors.

RESULTS

Higher awake and sleep SBPs predicted higher incidence of CVD in patients with and without diabetes. In multivariable analyses, elevated SBPs while awake and asleep predicted increased risk of CVD more accurately than clinic BP did, in both groups of patients. The relationships between ABP level and CVD were similar in both groups. In Kaplan-Meier analyses, the incidence of CVD in nondippers was similar to that in dippers, but risers experienced the highest risk of CVD in both groups (P < 0.01). The riser pattern was associated with a approximately 150% increase in risk of CVD, in both groups.

CONCLUSIONS

These findings suggest that ABPM is a better predictor of cardiovascular risk than clinic BP, and that this holds true for patients with or without T2DM.

Office and ambulatory blood pressure are independently associated with albuminuria in older subjects with type 2 diabetes

Blood pressure strongly predicts microalbuminuria and later progression to renal failure in people with diabetes. Ambulatory blood pressure monitoring seems to be superior to office blood pressure in predicting progression to microalbuminuria in type 1 diabetes. The associations of ambulatory blood pressure with office blood pressure and microalbuminuria in type 2 diabetes remain unclear. We studied the association of office blood pressure taken with an automated device and ambulatory blood pressure with spot urine albumin:creatinine ratio in 1180 older people with type 2 diabetes participating in the Informatics for Diabetes Education and Telemedicine Study. Office and awake systolic blood pressure were independently associated with albuminuria (P<0.001 for both) in a multivariate linear regression analysis that adjusted for age, gender, duration of diabetes, hemoglobin A1c, number of antihypertensive medications, and use of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. Twelve percent of participants had well-controlled office blood pressure but not ambulatory blood pressure, whereas 14% had well-controlled ambulatory but not office blood pressure. The prevalence of microalbuminuria and macroalbuminuria in these subgroups was intermediate between those with well-controlled or uncontrolled blood pressure by both methods. We found, in a multiethnic group of older subjects with type 2 diabetes, that office systolic blood pressure and awake systolic ambulatory blood pressure exhibited independent associations with degree of albuminuria.