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G F Watts

Publications and source records attributed to G F Watts.

173 records · Page 10Linked to original sources

Long-term variation of urinary albumin excretion in insulin-dependent diabetes mellitus: some practical recommendations for monitoring microalbuminuria.

Seven measurements of albumin excretion in overnight, recumbent (OR) and daytime, ambulant (DA) urine samples were carried out at successive intervals of 3 months in 172 insulin-dependent diabetic patients; at entry into the study, all had a resting albumin excretion rate less than 300 micrograms/min. Urinary albumin excretion in both collections was expressed as a concentration (UA, mg/l), as a creatinine ratio (UA/UC, mg/mmol) and as an excretion rate (UAV, micrograms/min). The pooled within-subject standard deviation (log. (base e) transformed data) for each expression of the albumin excretion was: (1) OR sample--UA 0.6824 mg/l, UA/UC 0.5257 mg/mmol, UAV 0.5940 micrograms/min; (2) DA sample--UA 0.7830 mg/l, UA/UC 0.5780 mg/mmol, UAV 0.6334 micrograms/min. The results were used to calculate the 95% range for a difference between two measurements within an individual patient which was lowest with OR UA/UC (chi/divided by 4.42) and highest with the DA UA (chi/divided by 9.16). Variation in the OR sample was also studied in terms of the patterns of microalbuminuria (M; UAV greater than 15 micrograms/min) which were found to be closely associated with the initial level of albumin excretion: persistent non-M was most common in patients with a baseline UAV less than 15 micrograms/min; established M was most common in those with a baseline UAV greater than 70 micrograms/min, some of whom developed clinical albuminuria. The frequency with which patients should be re-screened for M may be determined by the initial value of albumin excretion and by the threshold used to define M.

Adult↗

An examination of the covariability of subclinical albuminuria in insulin-dependent diabetes mellitus: implications for monitoring microalbuminuria.

We examined the covariability of subclinical albuminuria in a cohort of 160 insulin-dependent diabetics who underwent simultaneous measurements of overnight urinary albumin excretion rate (UAV) and several clinical variables on 7 occasions over a period of 18 months. After allowing for within-patient correlation between visits, significant within-patient associations were found between UAV and variations in tobacco consumption (regression coefficient = 0.006, S.E. = 0.002, P = 0.02), insulin dose (regression coefficient = 0.003, S.E. = 0.001, P = 0.01) and creatinine clearance (regression coefficient = 0.776, S.E. = 0.047, P < 0.0001); the association between UAV and creatinine clearance was not influenced by adjusting for urine flow rate. No significant associations were found between UAV and changes in blood pressure, glycaemic control or other variables. We then focused on 33 patients with intermittent microalbuminuria, defined as a UAV > 30 micrograms/min on at least one occasion, but not exceeding 3 consecutive occasions. These patients had a total of 52 episodes of microalbuminuria which were significantly associated at the 5% level with increases in creatinine clearance (P = 0.02), but not with changes in other variables. Our findings did not differ in patients with intermittent microalbuminuria defined with reference to a cut-off UAV of 20 micrograms/min. We conclude that changes in glomerular filtration rate (as reflected by creatinine clearance) may partly account for the within-patient variability in subclinical albuminuria in insulin-dependent diabetics, and that variables routinely measured in the clinic are not useful for deciding when to monitor patients for microalbuminuria.

Adolescent↗

Special article: non-invasive measurement of endothelial function.

1. Endothelial dysfunction, due to reductions in nitric oxide (NO) action, is an early feature of macrovascular disease. 2. Non-invasive measurement of endothelial function may be assessed by postischaemic dilation of forearm vessels, using plethysmography, or flow-mediated dilatation of the brachial artery, using ultrasound. 3. Brachial flow-mediated dilatation reflects NO release and/or action more than forearm hyperaemia. 4. These techniques have been used as surrogate measures of coronary endothelial function. 5. Methodological, physiological and clinical aspects of the techniques are discussed.

Animals↗

Serum lipids and lipoproteins in insulin-dependent diabetic patients with persistent microalbuminuria.

Serum lipid and lipoprotein concentrations were measured in 18 insulin-dependent diabetic patients with persistent microalbuminuria and an equal number with persistently normal albumin excretion. The groups were matched for sex, age, duration of diabetes, body mass index, insulin dose, and glycosylated haemoglobin. Diabetic patients with persistent microalbuminuria were found to have a significantly lower high density lipoprotein (HDL) cholesterol concentration (difference 0.29, 95% Cl 0.12 to 0.46, mmol l-1, p less than 0.01) and a higher low density lipoprotein (LDL) cholesterol:HDL cholesterol ratio (difference 0.97, 95% Cl 0.29 to 1.65, p less than 0.01) than patients with normal albumin excretion. No significant differences were found in total cholesterol, triglycerides, LDL cholesterol, apolipoprotein (apo) A-I and apo B concentrations. Compared to an age and sex-matched group of non-diabetic subjects with normal albumin excretion, diabetic patients with persistent microalbuminuria had significantly higher concentrations of total cholesterol (p less than 0.05), LDL cholesterol (p less than 0.05) and apo B (p less than 0.01), but a lower concentration of HDL cholesterol (p less than 0.05). No significant differences were found in serum lipids and lipoproteins between diabetic patients with normal albumin excretion and non-diabetic subjects.

Albuminuria↗

Effect of ketones and glucose on the estimation of urinary creatinine: implications for microalbuminuria screening.

The influence of acetoacetate, 3-hydroxybutyrate, and glucose on the assay of urinary creatinine by Jaffé-type and enzymatic methods was studied in vitro. Acetoacetate (greater than or equal to 5 mmol l-1) led to significant overestimation of low concentration urinary creatinine measured by an end-point and a kinetic Jaffé reaction, but neither 3-hydroxybutyrate nor glucose influenced these reactions. None of the metabolites interfered with an enzymatic creatininase assay. It is recommended that, when employing the urinary albumin/creatinine ratio to screen for microalbuminuria in diabetes mellitus, an enzymatic method be used to measure creatinine in Ketostix positive samples, particularly those that are dilute or obtained from patients with a low lean body mass.

3-Hydroxybutyric Acid↗

Urinary N-acetyl-beta-D-glucosaminidase excretion in insulin-dependent diabetes mellitus: relation to microalbuminuria, retinopathy and glycaemic control.

N-Acetyl-beta-D-glucosaminidase (NAG) excretion was measured in early morning urine samples from 133 Albustix-negative, normotensive insulin-dependent diabetic patients and 89 non-diabetic controls. Urinary NAG activity was determined using a chromogenic substrate, 2 methoxy-4-(2'-nitrovinyl)-phenyl 2-acetamido-3-deoxy-beta-D-glucopyranoside, and expressed as mumol MNP released/hour/mmol of creatinine. Overall, diabetic patients were found to have a significantly elevated mean urinary NAG activity (p less than 0.01) compared to controls. Within the diabetic patients urinary NAG activity was significantly elevated in patients with either microalbuminuria (p less than 0.001) or "poor" glycaemic control (p less than 0.001), but not in those with retinopathy (p = 0.117). Three-way analysis of variance revealed that the relationship of raised urinary NAG to microalbuminuria and "poor" glycaemic control were statistically independent. Elevated urinary NAG excretion in insulin-dependent diabetes mellitus appears to be associated with early diabetic nephropathy and poor long-term glycaemic control.

Acetylglucosaminidase↗

Paradise regained: insights into coronary heart disease prevention from recent clinical trials and basic research.

Many of the uncertainties regarding the place of lipid lowering in the prevention of coronary heart disease have recently been resolved. Some of the newer findings are reviewed, and the scope for a revised clinical approach examined. The results of trials of lipid lowering, based on clinical end-points and particularly on angiographic end-points, and their meta-analyses are discussed. The close relation between coronary-angiographic and clinical outcomes is reviewed in relation to recent advances in understanding of the underlying arterial pathology, and possible underlying mechanisms are proposed. The variables predictive of progression of coronary artery disease, including nutrient intake, are examined. The management of hyperlipidaemia requires that treatment and therapeutic goals are consonant with the patient's cardiovascular risk; for this purpose, clinical and biochemical assessment of risk may be enhanced by angiographic and non-invasive methods to detect potentially-infarctogenic atherosclerotic lesions.

Anticholesteremic Agents↗