A randomised controlled trial evaluating the effect of potassium supplementation on vascular function and the renin-angiotensin-aldosterone system.

There is limited evidence on the effect of potassium supplementation on the vasculature in patients at increased cardiovascular risk. Potassium increases aldosterone and there is a strong association of hyperaldosteronism with poor cardiac outcomes. We aimed to determine whether potassium supplementation has a significant medium-term effect on aldosterone levels and, if so, what the overall effect of this is on vascular function in patients at moderate cardiovascular disease risk. Forty patients at moderate cardiovascular disease risk were included in a randomised placebo-controlled crossover study. Patients were assigned to 64 mmol potassium chloride or placebo for 6 weeks. Vascular function was assessed using pulse-wave analysis including the detection of a change in augmentation index to salbutamol and nitroglycerine-induced vasodilation. There was no change in augmentation index with potassium vs placebo (25.2±1.4 vs. 26.0±1.3%, respectively). Potassium improved brachial systolic blood pressure (131.8±2.2 vs. 137.1±2.4 mm Hg; P=0.013), central systolic blood pressure (123.2±2.3 vs. 128.4±2.3 mm Hg; P=0.011) and central diastolic blood pressure (80.3±1.3 vs. 83.7±1.4 mm Hg; P=0.019). Plasma renin activity and serum aldosterone both increased with potassium (P=0.001 and P=0.048 respectively). We found that potassium supplementation had no effect on endothelial function or pulse-wave analysis. It lowered brachial systolic and central blood pressure. It was associated with increased plasma renin activity and serum aldosterone.

A case of euglyacemic diabetic ketoacidosis in a patient with gestational diabetes mellitus.

A 30-year old woman at 30 weeks gestation with insulin-controlled gestational diabetes was admitted with nausea and vomiting. Plasma glucose was 3.3 mmol/l with pH 7.23 and raised capillary ketones at 6.1 mmol/l. She was diagnosed with euglycaemic diabetic ketoacidosis. Cardiotocography showed good fetal movement and accelerations. She was given intramuscular betamethasone and started on intravenous dextrose, insulin and 0.9% saline with potassium chloride with resolution of ketosis. Euglycaemic diabetic ketoacidosis has been reported during pregnancy in patients with type 1 and type 2 diabetes. We believe that this is a report of such an occurrence in a patient with gestational diabetes.

A comparison of the use of urinary cortisol to creatinine ratios and nocturnal salivary cortisol in the evaluation of cyclicity in patients with Cushing's syndrome.

CONTEXT: Cyclical Cushing's syndrome is detected in our center by collecting sequential early morning urine (EMU) samples for cortisol to creatinine ratio over 28 d. The Endocrine Society suggests that nocturnal salivary cortisol (NSC) may be used to assess patients for cyclical Cushing's. However, there is only very limited evidence that it correlates with EMU testing or that it demonstrates cycling over 28 d. OBJECTIVE: We sought to correlate NSC with EMU results collected the following morning and to determine whether NSC could be used to detect cyclical Cushing's. DESIGN AND SETTING: An observation study of 28-d collections for NSC and EMU was performed in a tertiary referral center over 1 yr. PATIENTS: A 28-d collection of NSC and EMU was performed in 10 patients with confirmed or suspected Cushing's syndrome. MAIN OUTCOME MEASURE: The main outcome of the study was the correlation of salivary and urinary cortisol with graphical assessment of results for cycling. RESULTS: Eleven collections were performed. One patient with cyclical Cushing's completed the collection before and after cabergoline therapy. Two hundred seventy matched salivary and urinary results were correlated (r = 0.79; P < 0.001). In two patients with cyclical Cushing's, EMU and NSC followed a similar cyclical pattern. In one patient with recurrent cyclical Cushing's, cortisol was elevated in both saliva and urine but with more prominent cycles in saliva. CONCLUSION: NSC correlated well with EMU. NSC detected all cases of cyclical Cushing's. Therefore, NSC may prove to be an additional option or replacement for EMU in detecting cyclical Cushing's syndrome.

100 cases of primary aldosteronism: careful choice of patients for surgery using adrenal venous sampling and CT imaging results in excellent blood pressure and potassium outcomes.

OBJECTIVE: Patients with primary aldosteronism (PA) who are suitable for surgery should undergo adrenal computerised tomography (CT) and adrenal venous sampling (AVS). A retrospective study was performed of 100 patients with PA. We determined the optimal AVS lateralisation ratio for unilateral disease and reviewed adrenalectomy outcomes evaluating which characteristics predicted hypertension cure. METHODS: AVS was performed in 93 patients. Lateralisation criteria were assessed using ROC curve analysis. The outcome of adrenalectomy was reviewed in 39 patients and predictive factors for cure determined using univariate and multivariate analysis. RESULTS: Of previously published criteria, ROC curve analysis found a cortisol corrected aldosterone affected to unaffected (Aldo/Cort A:U) cut-off of 2·0 was the best predictor of adenoma identifying 80·4% of patients. A novel ratio calculated by dividing the affected to unaffected ratio by the unaffected to peripheral ratio [(Aldo/Cort A:U)/(Aldo/Cort U:IVC)] was successful in identifying 87·0% of patients. Cure rate for blood pressure after adrenalectomy was 38·5% with improvement in 59·0%. On univariate analysis, predictors of post-operative hypertension were increased weight, raised creatinine, left ventricular hypertrophy (LVH) and male sex. On multivariate analysis, male sex and higher pre-operative systolic blood pressure were predictive. CONCLUSIONS: Patients with PA should have CT scanning and AVS. Aldo/Cort A:U >2·0 is the most accurate of previously published ratios in predicting unilateral disease. When patients were carefully selected for surgery, 97% had cure or improvement in blood pressure control. Further confirmatory work is required on a novel ratio which was even more predictive in our series.

Diabetic nephropathy and chronic kidney disease at a busy diabetes clinic: a study of outpatient care and suggestions for improved care pathways at a subspecialty specialist diabetic renal clinic.

Prior to establishing a specialist diabetic renal clinic in our unit, we studied across 12 months all 1845 patients attending one of our diabetes clinics with a serum creatinine >150 µmol/l. Diabetic control was examined along with renal function and cardiovascular risk using current audit standards. 74 such patients were identified (male:female 54:20 mean HbA1c 7.8% (sd ± 1.45) and age 64.2 years (± 12.8). 30 patients had creatinine >200 µmol/l and 15 >250 µmol/l. Using the chronic kidney disease classification, 33, 28 and 6 patients were in groups III, IV and V with 7 patients undergoing renal replacement therapy. 65% of patients met JBS2 audit standards of blood pressure using a mean of 2.93 agents (sd ± 1.43). Ace-inhibitors or angiotensin receptor blockers were used in 81% and 81% were on regular antiplatelet or anticoagulant therapy. Audit standard for total cholesterol and LDL were met in 89% and 97% of patients respectively. All patients identified in our study were in CKD class III-V and therefore we considered also alternative inclusion criteria. 136 patients had a urinary ACR ≥ 30 mg/mmol. Using this and/or the serum creatinine level above identified 197 patients from the clinic. This study shows that measurement of serum creatinine alone is not sufficiently sensitive but extended criteria identified a 10% subgroup who will now be offered detailed assessments and intensified therapies at a subspecialty in-house renal clinic. eGFR has recently been added to our computerised proforma and will enable us to further refine inclusion criteria.