Blood pressure control--effects on diabetic nephropathy progression: how low does blood pressure have to be?

ALCAM a novel biomarker in patients with type 2 diabetes mellitus complicated with diabetic nephropathy

BACKGROUND & AIM

Activated leukocyte cell adhesion molecule (ALCAM/CD166) functions analogue to the receptor of advanced glycation end products, which has been implicated in the development of diabetic nephropathy (DN). We investigated the expression of ALCAM and its ligand S100B in patients with DN.

METHODS

A total of 34 non-diabetic patients, 29 patients with type 2 diabetes and normal albuminuria and 107 patients with type 2 diabetes complicated with DN were assessed for serum concentration of soluble ALCAM (sALCAM) by ELISA. Expression of ALCAM and S100B in kidney histology from patients with DN was determined by immunohistochemistry. Cell expression of ALCAM and S100B was analyzed through confocal immunofluorescence microscopy.

RESULTS

Serum concentration of sALCAM was increased in diabetic patients with DN compared to non-diabetic (59.85±14.99ng/ml vs. 126.88±66.45ng/ml, P<0.0001). Moreover sALCAM correlated positively with HbA1c (R=0.31, P<0.0001), as well as with the stages of chronic kidney disease and negatively correlated with eGFR (R=-0.20, P<0.05). In diabetic patients with normal albuminuria sALCAM was increased compared to patients with DN (126.88±66.45ng/ml vs. 197.50±37.17ng/ml, P<0.0001). In diabetic patients, ALCAM expression was significantly upregulated in both the glomeruli and tubules (P<0.001). ALCAM expression in the glomeruli correlated with presence of sclerosis (R=0.25, P<0.001) and localized mainly in the podocytes supporting the hypothesis that membrane bound ALCAM drives diabetic nephropathy and thus explaining sALCAM decrease in diabetic patients with DN. The expression of S100B was increased significantly in the glomeruli of diabetic patients (P<0.001), but not in the tubules. S100B was as well localized in the podocytes.

CONCLUSIONS

This study identifies for the first time ALCAM as a potential mediator in the late complications of diabetes in the kidney.

Urinary albumin excretion with sitagliptin compared to sulfonylurea as add on to metformin in type 2 diabetes patients with albuminuria: A real-world evidence study

AIM

To compare the change in urinary albumin to creatinine ratio (UACR) in type 2 diabetes (T2DM) patients with albuminuria who initiate sitagliptin to those who initiate a sulfonylurea (SU) as add-on to metformin monotherapy.

METHOD

A cohort of T2DM patients with albuminuria (UACR >30mg/g) who initiated sitagliptin or SU as add-on dual therapy to metformin between 2008 and 2014 was extracted from the computerized medical records of a large managed care organization in Israel. Patients with albuminuria and UACR measurements available at treatment initiation and 120-365days afterwards were included. Propensity scores were calculated based on 17 factors, including demography, comorbidities, baseline levels of HbA1c, UACR, BMI, eGFR, and ACE/ARB use, and patients were matched in a 1:1 ratio. Changes in UACR were compared between the matched pairs using generalized estimating equations.

RESULTS

A total of 282 eligible pairs (sitagliptin:SU) were identified. During a mean follow-up of 9months, median UACR changes were -35% (IQR=-73% to 5%) and -31% (IQR=-72% to 21%) in the sitagliptin and SU groups, respectively. Mean absolute HbA1c reductions among sitagliptin and SU groups were 0.9% and 1.0%, respectively. The magnitude of UACR reduction generally increased with greater magnitude of HbA1c reduction in both treatment groups. However, after controlling for HbA1c reduction and the interaction between HbA1c reduction and UACR reduction, sitagliptin users demonstrated a trend toward an increased likelihood of UACR reduction compared to SU users (odds ratio=1.20; 95% confidence interval: 0.99-1.47, P=0.063).

CONCLUSION

Our results suggest that both sitagliptin and SU reduce albuminuria as an add-on therapy to metformin, but that sitagliptin may provide greater reductions in albuminuria independent of glycemic control when compared to SU. Larger population studies are required to further explore this.

Diabetes and Hypertension: Epidemiology of the Relationship and Pathophysiology of Factors Associated With These Comorbid Conditions

Diabetes and hypertension frequently coexist, leading to additive increases in the risk of life-threatening cardiovascular events. Hypertension is a common comorbid condition in patients with type 1 or type 2 diabetes when compared with the general population and occurs in 75% of patients with the more prevalent form of diabetes, type 2. Arterial blood pressure plays an important role in the development of renal damage and presents a complex relationship. It is well-known that hypertension accelerates the course of microvascular and macrovascular complications of diabetes and that hypertension often precedes type 2 diabetes and vice versa. Patients with type 1 and 2 diabetes and nephropathy frequently have circadian changes in blood pressure that correlate to nephropathy risk. Early detection of nocturnal hypertension and early intervention with angiotensin blockade may delay progression of diabetic nephropathy.