Circadian changes in blood pressure and their relationships to the development of microalbuminuria in type 1 diabetic patients

Cardiovascular autonomic neuropathy and the impact on progression of diabetic kidney disease in type 1 diabetes

INTRODUCTION

We investigated the association between cardiovascular autonomic neuropathy (CAN) and decline in kidney function in type 1 diabetes.

RESEARCH DESIGN AND METHODS

We included 329 persons with type 1 diabetes. CAN was assessed by cardiovascular reflex tests (CARTs): heart rate response to deep breathing (E/I ratio), to standing (30/15 ratio) and to the Valsalva maneuvre. Two or more pathological CARTs defined CAN diagnosis. Outcomes were yearly change in albuminuria or yearly change in estimated glomerular filtration rate (eGFR). An endpoint of eGFR decline >30%, development of end-stage kidney disease (ESKD) or death was examined.Associations were assessed by linear and Cox regression.

RESULTS

Participants were aged 55.2 (9.4) years, 52% were male, with a diabetes duration of 40.1 (8.9) years, HbA_1c of 7.9% (62.5 mmol/mol), eGFR 77.9 (27.7) mL/min/1.73 m², urinary albumin excretion rate of 14.5 (7-58) mg/24 hours, and 31% were diagnosed with CAN.CAN was associated with a 7.8% higher albuminuria increase per year (95% CI: 0.50% to 15.63%, p=0.036) versus no CAN. The endpoint of ESKD, all-cause mortality and ≥30% decline in eGFR was associated with CAN (HR=2.497, p=0.0254).

CONCLUSION

CAN and sympathetic dysfunction were associated with increase in albuminuria in individuals with type 1 diabetes suggesting its role as a potential marker of diabetic kidney disease progression.

[Renal function and blood pressure in type 1 diabetes mellitus]

INTRODUCTION

Persistent microalbuminuria is the accepted marker for early detection of a high risk of developing diabetic nephropathy in patients diagnosed with Type I Diabetes mellitus. The Ambulatory Blood Pressure Monitoring (ABPM) evaluates the circadian variations of blood pressure while awake and asleep.

OBJECTIVE

To show the renal function characteristics and the data provided by ABPM in a cohort of insulin dependent diabetic children referred to our hospital.

MATERIAL AND METHODS

A total of 61 patients with an age range between 6 and 17 years were studied. In each child blood pressure monitoring was arranged, the glomerular filtration rate in 24 hour urine was estimated, and glycosylated haemoglobin (HbA1c), total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, was measured.

RESULTS

None of the cases showed persistent microalbuminuria. The renal function showed an increase in the glomerular filtration rate (146.6 ±22 ml/minute/1.73 m(2)). In 39% of the cases there was no drop in systolic blood pressure during the night, whereas 11% of the patients in our series had a decrease in diastolic pressure. The cases were analysed depending on whether or not there had been a physiological arterial or diastolic pressure drop during the night: there were no significant differences in anthropometric data, glycosylated haemoglobin (HbA1c) levels, total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, glomerular filtration rate (GFR), proteinuria and microalbuminuria between both groups.

CONCLUSION

In Type I Diabetes Mellitus a decrease in the physiological blood pressure during the night is a frequent finding. There is also an increase in the glomerular filtration rate.

Posttraumatic stress disorder and nocturnal blood pressure dipping in young adult African Americans

OBJECTIVE

To evaluate the relationship between posttraumatic stress disorder (PTSD) and nocturnal blood pressure (BP) dipping in young adult African Americans (AAs). PTSD is associated with physical illnesses including cardiovascular conditions. Sleep disturbances related to heightened arousal likely contribute to physical health risk; however, this possibility has not been studied. The studies that have found a relationship between PTSD and hypertension (HTN) have substantial representation of AAs. AAs have elevated rates of HTN and are more likely to exhibit an absence of the normal "dip" of BP at night. Nocturnal BP "nondipping" is an established risk factor for HTN and its cardiovascular complications. Nocturnal BP nondipping and sleep disturbances of PTSD have both been linked to sympathetic nervous system function.

METHODS

Thirty healthy young adult AAs (60% female; mean age = 20.0 years; 17 with lifetime full or subthreshold PTSD, 4 with current symptoms) received 24-hour BP and actigraphy monitoring, filled out sleep diaries, and had structured clinical assessment of PTSD.

RESULTS

There were significant associations of lifetime full and subthreshold PTSD and BP nondipping, and the degree of nocturnal dipping correlated with lifetime and current PTSD severity.

CONCLUSION

Elevated nocturnal BP may be a link between PTSD and cardiovascular morbidity in AAs that can be targeted in prevention.

Predicting the development of diabetic nephropathy and its progression

Diabetes remains the number one cause of end-stage renal disease worldwide. Only about one third of diabetic patients develop nephropathy, and the risk appears to be, in part, genetically determined. In this article, we review clinical and genetic markers for the development and progression of diabetic nephropathy. Microalbuminuria remains the best available predictor of the subsequent development of nephropathy, even though in recent years it has become clear that less than 50% of individuals with type 1 diabetes progress to overt proteinuria over a period of less than 10 years. It is of great interest for early recognition of risk of nephropathy that small elevations in nighttime blood pressure predict microalbuminuria in type 1 diabetes. Genetic markers for diabetic nephropathy have not been conclusively identified. The occurrence of renal events in diabetic patients, however, appears to be influenced by the angiotensin-converting enzyme (ACE) genotype, with a dominant deleterious effect of the D allele (D/D or I/D) versus I/I genotype. Some patients with the DD genotype also appear less susceptible to the renoprotective effects of conventional doses of ACE inhibitors, suggesting that ACE genotyping might be useful in selecting those patients that could benefit from higher doses of ACE inhibitors and more aggressive treatment to prevent or delay disease progression.