Postexercise albuminuria in children with different duration of type-1 diabetes mellitus

Hypertension is associated with increased post-exercise albuminuria, which may be attenuated by an active lifestyle

Albuminuria is a known marker for endothelial dysfunction and cardiovascular events, even below the threshold of moderately increased albuminuria (MIA). Post-exercise increased albuminuria may precede the appearance of rest MIA, enabling detection of early injury. Modifying lifestyle for a population at risk for MIA is therefore of interest. Our aim was to evaluate post-exercise albuminuria in hypertensive compared with normotensive individuals and to analyze the effect of an active lifestyle on rest and post-exercise albumin excretion. The study cohort consisted of 3931 adults who participated in a health-screening program. Albuminuria was measured as urine albumin-to-creatinine ratio (ACR). Lifestyle was divided into three groups: non-active, less-active, and active according to regular sport activity, categorized as follows: none, <2.5 and ≥2.5 hours per week. Mean age was 47.7 years, and 31.2% (n = 1228) were diagnosed with hypertension. Both rest and post-exercise ACR were higher in hypertensive compared to normotensive participants. Rest ACR was higher in non-active compared to less-active and active hypertensive participants. Hypertensive participants with an active lifestyle had significantly lower post-exercise and delta ACR compared to less-active and non-active hypertensive participants. Parameters related to delta ACR in hypertensive participants were increased age, BMI, and diabetes, while active lifestyle and fitness (measured as METS achieved by a stress test) were protective. In conclusion, there is an association between hypertension and increased albumin excretion post-exercise, which can be attenuated with an active lifestyle.

Sex difference in the risk for exercise-induced albuminuria correlates with hemoglobin A1C and abnormal exercise ECG test findings

BACKGROUND

Albuminuria is an established marker for endothelial dysfunction and cardiovascular risk in diabetes and prediabetes. Exercise induced albuminuria (EiA) appears earlier and may be a more sensitive biomarker for renal endothelial damage. We sought to examine the association between EiA, parameters of the metabolic syndrome, A1C levels, exercise ECG test results and sex related differences in a large cohort of healthy, pre-diabetic and diabetic subjects.

METHODS

A total of 3029 participants from the Tel-Aviv Medical Center Inflammation Survey cohort (mean age 46 years, 73% men) were analyzed. Multiple physiologic and metabolic parameters including A1C were collected and albuminuria was measured in all subjects before and immediately after completing an exercise ECG test.

RESULTS

Exercise increased urinary albumin to creatinine ratio (ΔEiA) by 2.8 (0-13.6) mg/g for median (IQR) compared to rest albuminuria (p < 0.001). An increase in ΔEiA was observed with accumulating parameters of the metabolic syndrome. ΔEiA showed significant interaction with sex and A1C levels; i.e. women with A1C > 6.5% had an increased risk of higher ΔEiA (p < 0.001). Using a cutoff of ΔEiA > 13 mg/g (top quartile) we found that women with ΔEiA > 13 mg/g were at greater risk for abnormal exercise ECG findings, (OR = 2.7, p = 0.001).

CONCLUSION

Exercise promotes excessive urinary albumin excretion in dysmetabolic patients. In women, a significant correlation exists between ΔEiA and A1C levels. A cutoff of ΔEiA > 13 mg/g in women may be used to identify populations at risk for abnormal exercise ECG test findings and perhaps increased cardiovascular risk. Future studies will be needed to further validate the usefulness of ΔEiA as a biomarker for cardiovascular risk in women with and without diabetes.

Effect of exercise intensity on albuminuria in adolescents with Type 1 diabetes mellitus

AIMS

Exercise may be useful to detect patients with diabetes prone to develop persistent microalbuminuria. We studied the relationship between exercise intensity, measured as maximal oxygen consumption (VO(2)max), and microalbuminuria in patients with Type 1 diabetes mellitus patients.

METHODS

We studied 10 patients, age range 10-18 years, with Type 1 diabetes who were normotensive and normoalbuminuric, with less than 10 years since diagnosis. Patients had normal renal function, without infections or clinical evidence of complications. Metabolic control was intensively adjusted in all patients. They underwent three consecutive physical exercise tests, reaching 100, 80 and 60% of the maximal cardiac frequency response.

RESULTS

Eight patients had adequate to regular metabolic control. All patients had lower than predicted VO(2)max values. At 60%, only three patients showed microalbuminuria in excess of 20 μg/min, two of them had inadequate metabolic control. Post-exercise microalbuminuria exceeded normal values in nine, seven and three patients when submitted to 100, 80 and 60% of exercise intensity, respectively.

CONCLUSIONS

Microalbuminuria increased with exercise intensity. Sex, body composition and VO(2)max were the main factors associated with microalbuminuria. The prognostic significance of albuminuria induced by intense exercise in these subjects with Type 1 diabetes is not yet known.

Measurement, Interpretation, and Implications of Proteinuria and Albuminuria

Proteinuria is a common disorder in dogs and cats that can indicate the presence of chronic kidney disease (CKD) before the onset of azotemia or the presence of more severe CKD after the onset of azotemia. Although a direct pathogenetic link between glomerular disease, proteinuria, and progressive renal damage has not been established, attenuation of proteinuria has been associated with decreased renal functional decline in several studies. There is a need to continue to increase our understanding of the effects of proteinuria on the glomerulus, the tubule, and the interstitium in dogs and cats.

Early Detection of Renal Damage and Disease in Dogs and Cats

Renal damage and disease can be caused by acute or chronic insults to the kidney. Acute renal damage often results from ischemic or toxic insults and usually affects the tubular portion of the nephron. In contrast, chronic renal disease can be caused by diseases and/or disorders that affect any portion of the nephron, including its blood supply and supporting interstitium. Early detection of acute renal disease facilitates appropriate intervention that can arrest or at least attenuate tubular cell damage and the development of established acute renal failure. Similarly,early detection of chronic renal disease, before the onset of renal azotemia and chronic renal failure, should facilitate appropriate intervention that stabilizes renal function or at least slows its progressive decline.

Stress tolerance test and SDS-PAGE for the analysis of urinary proteins in children and youths

Excretion of urinary proteins (UP) is an important marker for the evaluation of patients with progressive renal disease. In order to analyze quantitative and qualitative variability of UP in relation to physical activity, we used standardized stress tolerance test and SDS-PAGE. Five urine samples were obtained from each patient at rest, during ordinary daily activity and after physical stress. Determination of total proteins was performed using Meulman's classic method with sulfosalicylic acid. UP were separated by ultrathin horizontal gradient SDS-PAGE according to Görg. There were 142 patients; 40 with poststreptococcal glomerulonephritis (PSGN), 11 with diabetes mellitus, 16 with chronic pyelonephritis and 75 who attended for investigation of asymptomatic proteinuria. Functional proteinuria was established in 42 subjects, who displayed maximal UP excretion during stress and the presence of apolipoprotein AI on SDS-PAGE. Children with PSGN showed no significant increase of UP during stress. Some children with diabetes mellitus (27%) and chronic pyelonephritis (47%) displayed microproteinuria or overt proteinuria after stress. Quantitative and qualitative changes in total UP excretion can be detected by stress tolerance test and SDS-PAGE. It remains to be seen whether stress tolerance test can identify children and youths who are at higher risk for disease progression.