Biomedical subjects

C Tsalamandris

Publications and source records attributed to C Tsalamandris.

24 records · Page 2Linked to original sources

PubMed1993

Long-term glycemic control and the rate of progression of early diabetic kidney disease.

In this prospective study of 11.9 years duration (range 9 to 14), we examined the progression of albuminuria prior to and after the onset of microalbuminuria [albumin excretion rate (AER): 20 to 200 micrograms/minute]. Glycated hemoglobin (HbA1), AER and blood pressure were measured every six months. Twenty-two (13 type I, 9 type II) patients were identified in whom AER increased progressively (progressors). These patients were compared with 22 others matched for age, duration and type of diabetes in whom AER did not change significantly during the study period (non-progressors). In the progressors, the rate of increase in AER correlated with mean HbA1 for the study period in patients with type I (r = 0.68, P < 0.01) and type II diabetes (r = 0.71, P < 0.05). Furthermore, AER began increasing well before the conventional 20 micrograms/minute threshold of microalbuminuria had been reached and within the first five years of diagnosis of type I diabetes. We conclude that in predisposed diabetic patients, long-term glycemic control is correlated with the rate of development of early renal abnormalities. Repeated measurements of AER from the time of diagnosis may be useful in the early detection of patients who will develop microalbuminuria and ultimately overt diabetic nephropathy.

Adolescent↗

PubMed1993

Peak bone mass, a growing problem?

The focus of attention in osteoporosis research has been on factors influencing bone fragility and the propensity for trauma (falls) during adulthood and old age. The purpose of this review is to change the focus of this attention toward consideration of skeletal growth in the first 20 years of life and to demonstrate the importance of mineral accrual (and the factors influencing this accrual) in determining bone density in adulthood and old age. We suggest that the epidemiology of fractures may be unified by a central role of reduced peak bone density in the pathogenesis of the low bone density found in patients with fractures. The reduced peak bone density establishes the relevance of age-related and sex hormone-dependent bone loss. Risk and protective factors in the first 20 years of life may have quantitatively larger, and qualitatively different effects on the axial and appendicular skeleton than exposure during adulthood. Public health measures focussed on optimising mineral accrual in the first 20 years of life may be more important than health care measures more proximate to the age at which fractures occur.

Adolescent↗

PubMed1992

Osteoporosis in anorexia nervosa: the influence of peak bone density, bone loss, oral contraceptive use, and exercise.

Anorexia nervosa occurs early in life and predisposes to osteoporosis. Exercise may be protective. We asked: (1) Does failure to attain peak bone density contribute to the deficit in bone density? (2) Does oral contraceptive use protect against osteoporosis? (3) Is any protective effect of exercise confined to weight-bearing sites? Areal bone density (g/cm2) and body composition were measured by dual x-ray absorptiometry in 65 patients with anorexia nervosa and 52 controls. Comparing the 12 patients with primary amenorrhea and the 37 patients with secondary amenorrhea, bone density (mean +/- SEM) at the lumbar spine was 0.88 +/- 0.04 versus 1.06 +/- 0.03 (P = 0.001), respectively. Bone density at the femoral neck was 0.80 +/- 0.04 versus 0.92 +/- 0.03 (P < 0.05), respectively. These values differed before, but not after, adjusting for the respective duration of illness (73.0 +/- 10.3 versus 34.1 +/- 4.8 months, P < 0.001) and fat-free mass (31.6 +/- 1.3 versus 35.4 +/- 0.5 kg, P < 0.01). Bone density at the lumbar spine in the 16 patients with 31.8 +/- 8.3 months of contraceptive exposure was higher than in the 49 patients with no contraceptive exposure (1.14 +/- 0.05 versus 1.02 +/- 0.02 P < 0.02) but was lower than in controls (1.14 +/- 0.05 versus 1.27 +/- 1.02, P < 0.01). No protective effect of contraceptive exposure was detectable at the femoral neck.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1992

Angiotensin converting enzyme inhibition and calcium channel blockade in incipient diabetic nephropathy. The Melbourne Diabetic Nephropathy Study Group.

Small increases in blood pressure are a feature of incipient diabetic nephropathy, and mean blood pressure often correlates with the degree of albuminuria in such patients. Antihypertensive therapy with angiotensin converting enzyme inhibitors (CEI) or calcium channel blockers (CCB) has been assessed in several studies to determine if either form of treatment modifies incipient diabetic nephropathy and its evolution to established nephropathy. The acute renal hemodynamic effects of CEI differ from those of CCB under certain circumstances. In incipient diabetic nephropathy, therapy with CEI but not CCB tends to reduce filtration fraction, especially in hyperfiltering patients. In hypertensive patients with incipient diabetic nephropathy, both treatments result in a decrease in albuminuria and the responses are mainly dependent on the lowering of systemic blood pressure. In normotensive patients with incipient diabetic nephropathy, a lowering of mean blood pressure with CEI or CCB is not found consistently while effects on albuminuria are difficult to interpret. Short- and long-term therapy with CEI lowers or stabilizes albuminuria. Short-term administration of CCB has at times been associated with increases in albuminuria, but a comparison of CEI and CCB over 12 months in the Melbourne Diabetic Nephropathy Study (MDNS) has shown that both drugs stabilize albuminuria with no significant differences in their effects. Serial analysis of urinary sodium excretion in the MDNS shows that the hypotensive response to CEI in incipient nephropathy is highly dependent on sodium intake, and that sodium intake may modulate albuminuria during both CEI and CCB therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗

PubMedDate not supplied

Prediction of persistent microalbuminuria in patients with diabetes mellitus.

Persistent microalbuminuria [albumin excretion rate (AER): 30-300 micrograms/min] is predictive of clinical nephropathy in patients with insulin-dependent diabetes mellitus (IDDM) and cardiovascular mortality in addition to nephropathy in patients with non-insulin-dependent diabetes. The clinical significance of intermittent microalbuminuria, however, is unknown. We performed serial measurements of urinary albumin excretion at intervals of approximately 6 months in 139 diabetic patients who at entry did not have persistent microalbuminuria to determine whether intermittent microalbuminuria occurs more frequently in those patients who subsequently develop persistent microalbuminuria. The relative risk for the development of persistent microalbuminuria in diabetic patients with a greater proportion than 3 out of 20 determinations in the microalbuminuric range was 17.4 (95% confidence interval, 3.92-77.2) in those with IDDM and 2.78 (0.99-7.8) in those with non-insulin-dependent diabetes when compared with matched diabetic patients with fewer elevated measurements. These data suggest that frequent intermittent microalbuminuria predicts the future development of persistent microalbuminuria particularly in IDDM patients and that AER should be assessed by serial rather than single measurements.

Adolescent↗

PubMedDate not supplied

Long-term intraindividual variability of serum lipids in patients with type I and type II diabetes.

The objective of this study was to estimate the long-term intraindividual variability of lipid levels in adult type I and type II diabetic patients. Total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and hemoglobin A1c were measured every 3-6 months in 135 patients attending the Austin Hospital diabetes clinic. Analysis was performed on 60 diabetic patients (33 type I and 27 type II) who had not been treated with lipid lowering drugs and who met the inclusion criteria of at least five measurements [mean +/- standard error of the mean (SEM), 9.5 +/- 0.4; range, 5-17] collected over a minimum of 4 years (5.1 +/- 0.1; 4-6.5 years). Total variability, expressed as coefficient of variation, was 8.8 +/- 0.4% for total cholesterol, 23.9 +/- 1.5% for triglycerides, 10.2 +/- 0.5% for HDL cholesterol, and 12.0 +/- 0.5% for LDL cholesterol. Biological variability, derived from total and analytical variability, was higher than previous estimates in nondiabetic subjects for total cholesterol and HDL cholesterol but similar for triglycerides and LDL cholesterol. No relationship was observed between total lipid variability and diabetes type, age, baseline or mean lipid levels, duration of follow-up, or the number of samples per patient. Men demonstrated greater variability than women for total cholesterol (men 9.5 +/- 0.5%, n = 34, women 7.9 +/- 0.5%, n = 26, p < 0.01) and triglycerides (men 26.5 +/- 2.2%, women 20.4 +/- 1.4%, p = 0.03). Total lipid variability was also unrelated to baseline or mean hemoglobin A1c or to the change in hemoglobin A1c during the study as a whole. However, the change in hemoglobin A1c was associated with the change in total cholesterol (r = 0.30, p < 0.03) and the change in LDL cholesterol (r = 0.27, p < 0.05). In conclusion, long-term intraindividual lipid variability in adult diabetic subjects is higher for total and HDL cholesterol than previously published values in nondiabetic subjects. Variability of triglycerides is at least double that of total cholesterol, HDL cholesterol and LDL cholesterol. Biological variability, not measurement error, accounts for the greatest proportion of total variability for all lipid parameters. Confidence levels calculated from these data have implications for the initiation of lipid lowering therapy and in monitoring the effects of intervention.

Adult↗