Peripheral obstructive arterial disease and carotid artery stenosis in end stage renal disease: a case-control study

AIM

Cardiovascular diseases are an important cause of morbidity and mortality in end stage renal disease (ESRD) patients. The purpose of this study was to evaluate the predominance of carotid stenosis and peripheral obstructive arterial disease (POAD) in a group of patients subject to dialysis compared with a control group.

METHODS

It is a control-case study performed on patients at different hemodialysis facilities; the exams were carried out in ambulatory care. Two groups of patients were examined, the first group was made up of 40 dialysis patients (46.6% men, average age 58.8), the second was the control group made up of 58 subjects matched by age, sex, arterial pressure, presence of diabetes and smoking habits. All patients underwent an Eco-Color Doppler exam on the over aortal trunks and lower extremities and had their Ankle-Brakial-Index (ABI) measured. Carotid stenosis was considered only if equal or over 50%.

RESULTS

Twenty percent of dialysis patients showed carotid stenosis (CS) versus 12% in the control group, with an OR of 7.9 (CI 95% 1.3-47.7) adjusted to sex, age and hypertension. The ultrasound picture of the lesions showed large amounts of calcium deposits. Predominance of POAD in dialysis patients was 20% versus 9% in the control group. In dialysis patients the OR adjusted to age, sex and arterial pressure was 6.3 (CI 95%, 1.2-32.6).

CONCLUSION

The ultrasound picture of the lesions showed mainly underpopliteal lesions with ''rosary bead'' calcifications. In diabetic dialysis patients the OR was 7.6 (CI 95% 1.4-46.3).

Urinary composition and lithogenic risk in normal subjects following oligomineral versus bicarbonate-alkaline high calcium mineral water intake

OBJECTIVE

A normal dietary calcium intake to reduce intestinal oxalate absorption is essential to avoid recurrence of calcium oxalate stone formation. It is also important in the prevention of osteopenia in idiopathic hypercalciuria. The calcium content of waters used for hydration may vary from very low to relatively high and is an important factor in prevention or additional risk of stone formation. Therefore, the effect of drinking mineral waters of different calcium concentrations on lithogenic risk factors was studied in normal volunteers.

MATERIALS AND METHODS

Normal subjects were divided into two groups of 11 and 10 individuals each. All followed a prescribed diet with an average calcium content of 800 mg/day. The water intake for hydration consisted of 2 liters of an oligomineral water with a low calcium content, <20 mg/l (group A) or of a bicarbonate alkaline water with a high calcium content, 370 mg/l (group B).

RESULTS

Diuresis increased similarly in both groups; urine calcium increased by about 80 mg/day in group B. A rise in urine oxalate was observed in both groups, along with the increased urine volume. Osmolar excretion increased in group B; urine osmolality decreased significantly only in group A. In spite of the increase in calciuria in group B, Ca/citrate ratio was constant, due to an increase in citrate excretion. Inter-group differences in terms of activity products of calcium phosphate, calculated according with Tiselius's methods, were found. The differences in AP(CaP) index 1 and AP(CaP) index 2 were significant, with higher values in group B, who drank the bicarbonate alkaline mineral water.

CONCLUSIONS

Increased water intake between meals to prevent renal stone recurrence should preferably be achieved with a relatively low calcium water and calcium-rich mineral waters should be avoided.