Metolazone and bendroflumethiazide in hypertension: physiologic and metabolic observations.

A double-blind crossover comparison was made in 18 nonedematous hypertensive subjects with glomerular filtration rates exceeding 70 ml/min/1.73 m2 of the effects of 5 mg metolazone and 5 mg bendroflumethiazide on blood pressure and metabolic parameters. After a 4-wk run-in placebo period, patients received either metolazone or bendroflumethiazide for 6 wk in a crossover fashion with an intervening washout period of 4 wk. Metolazone induced a more sustained and greater blood pressure response than bendroflumethiazide. Changes in plasma potassium, urate, bicarbonate, renin, and angiotensin II occurred during treatment with both metolazone and bendroflumethiazide; the only significant difference, however, was in changes in plasma bicarbonate. Total body potassium (TBK), measured by whole-body monitor, did not fall outside the normal range with either metolazone or bendroflumethiazide, although metolazone induced a greater reduction in TBK (6.2 gm, 5.5% of TBK) than bendroflumethiazide (1.2 gm, 1.1% of TBK, p < 0.05). Our results suggest that metolazone is a more effective antihypertensive and induces similar but greater metabolic changes than bendroflumethiazide. The results of our comparison suggest that although changes in plasma potassium and TBK are minor, they are greater with metolazone, and potassium supplements may not be necessary in nonedematous hypertensive patients with normal renal function.

Abnormal haemostasis and blood viscosity in malignant hypertension.

We have previously shown abnormalities of haemostasis suggestive of intravascular coagulation in patients with malignant hypertension, a condition associated with retinopathy and renal fibrin deposition. To determine whether such abnormalities are specific to malignant hypertension, we have measured several haemostatic and haemorheological variables in 18 patients with malignant hypertension (Group 1), 18 matched healthy controls (Group 2), and 18 patients with non-malignant hypertension (Group 3) matched for renal pathology, blood pressure and serum creatinine with Group 1. Both Groups 1 and 3 had increased mean levels of fibrinogen, factor VIIIc, beta-thromboglobulin, plasma viscosity and blood viscosity (corrected for haematocrit); and decreased mean levels of haematocrit, antithrombin III and platelet count. Mean levels of fast antiplasmin and alpha2-macroglobulin were elevated in Group 1 but not in Group 3. We conclude that most blood abnormalities are not specific to malignant hypertension; are also present in patients with non-malignant hypertension who have similar levels of blood pressure and renal damage; and might result from renal damage as well as promoting further renal damage by enhancing fibrin deposition. However increased levels of fibrinolytic inhibitors in malignant hypertension merit further investigation in relation to removal of renal fibrin.

Serum -macroglobulins in renal disease and preeclampsia.

The serum levels of alpha(2)-macroglobulin and pregnancy-associated globulin (another alpha-macroglobulin) have been measured by means of a radial immunodiffusion technique in (1) renal disease with and without proteinuria, (2) in age- and sex-matched controls, (3) in preeclampsia with and without proteinuria, and (4) in normal pregnant controls. There are significant increases in alpha(2)-macroglobulin and pregnancy-associated globulin in renal disease accompanied by proteinuria but normal levels are found in renal disease without proteinuria. Compared with normal pregnancy, alpha(2)-macroglobulin is significantly raised in preeclampsia with proteinuria but normal in preeclampsia without proteinuria. In contrast, serum pregnancy-associated globulin is significantly reduced in preeclampsia both with and without proteinuria when compared with normal pregnancy.

Relationship between haemoglobin and the other clinical and laboratory parameters in rheumatoid arthritis.

A retrospective study is reported of 160 patients with definite or classical rheumatoid arthritis, in which changes in haemoglobin concentration were analysed against changes in various routine clinical and laboratory indices of disease activity over a period of time. Although statistically significant correlations were found between haemoglobin concentrations and the articular index of joint tenderness, serum albumin concentration, and erythrocyte sedimentation rate at one point in time, significant relationships in changes in haemoglobin concentration were only found with changes in the latter two laboratory indices. The significant correlations were weak and less important than the cumulative effect of unknown variables in determining haemoglobin level. The study shows that the routine clinical and laboratory parameters of disease activity in rheumatoid arthritis are of no value in predicting the haemoglobin concentration.

Abnormalities in mineral metabolism suggestive of parathyroid over-activity in rheumatoid arthritis.

A three-part study on mineral metabolism in patients with classical rheumatoid arthritis is described. In the first two parts, biochemical abnormalities were revealed suggestive of parathyroid over-activity, and in the third part, observation on calcium absorption provides a hyperparathyroid pattern. The importance of these findings in relation to demineralisation of bone in rheumatoid arthritis is discussed.

Diphtheroid peritonitis associated with continuous ambulatory peritoneal dialysis.

Five patients on continuous ambulatory peritoneal dialysis (CAPD) developed peritonitis caused by diphtheroid bacteria. Peritoneal catheter exit site inflammation and/or discharge preceded all cases and relapses were common. Antimicrobial therapy alone failed to eradicate the bacteria and peritoneal catheter removal was required before peritonitis resolved. Laboratory culture of the diphtheroid bacteria was difficult and prolonged incubation was often necessary. Diphtheroid bacteria are important opportunistic pathogens in immunocompromised patients and should be carefully sought for in all cases of culture-negative CAPD-associated peritonitis.

Whole body aluminium in chronic renal failure and dialysis encephalopathy.

Whole body calcium, phosphorus and nitrogen have been measured by in vivo neutron activation analysis in patients with chronic renal failure, including 9 with dialysis encephalopathy. Aluminium was also activated by this procedure, but to the same radioactive product as that from phosphorus: its presence was therefore detected as an increase in the apparent total body phosphorus above that expected for a person with the same calcium content. Patients with dialysis encephalopathy had slightly more apparent phosphorus than others with chronic renal failure, although the difference was not statistically significant. This difference corresponded to an excess of aluminium not greater than 3.3 g(95% confidence limit) which places an upper limit on excess aluminium accumulation in this condition.

Dissected popliteal cyst: an unusual presentation of acute gout.

A 46-year-old man with acute gout and a dissected popliteal cyst presented with clinical features which mimicked rheumatoid arthritis and thrombophlebitis. The clinical and laboratory diagnosis of the case are presented and similar cases previously reported are briefly reviewed.

Dissected popliteal cyst: an unusual presentation of acute gout.

A forty-six year old man with acute gout and a dissected popliteal cyst presented with clinical features which mimicked rheumatoid arthritis and thrombophlebitis. The clinical and laboratory diagnosis of the case are presented and similar cases previously reported are briefly reviewed.

Serum uric acid levels in England and Scotland.

A survey of serum uric acid levels in 766 subjects in England and 337 in Glasgow was carried out. There was no difference in the frequency distribution of uric acid or the mean levels in the two countries. A serum uric acid of 7 mg/100 ml or over was found in 7.2% of the men and 0.4% of the women. The previously described sex difference and association of serum uric acid with weight were confirmed. No association was found with social class. The suggestion of an increase in uric acid levels in the United Kingdom over the past 14 years is discussed.