Biomedical subjects

K Karavanaki

Publications and source records attributed to K Karavanaki.

9 recordsLinked to original sources

PubMed2003

Coexistence of impaired indices of autonomic neuropathy and diabetic nephropathy in a cohort of children with type 1 diabetes mellitus.

One hundred and twenty-nine (87%) out of a county population of 150 eligible children with type 1 diabetes mellitus (DM) and 144 age- and sex-matched control children participated in a longitudinal, epidemiological study of the evolution of diabetic microvascular disease. The mean (SD) age of the children with DM was 12.4 (+/- 3.4) years with a mean DM duration of 4.5 (+/- 3.2) years and a mean HbA1c of 11.1 (+/- 2.2)%. Two sets of measurements were made over a period of 18 months. Pupillary adaptation in darkness (PD), as an index of sympathetic dysfunction, was assessed using a portable Polaroid pupillometer. Urinary albumin excretion, as an index of incipient nephropathy, was assessed in children with DM from a fraction of all voidings during two separate 48-h periods and was expressed as urinary albumin/creatinine ratio (A/C). Heart rate variation (HRV), as an index of cardiovascular autonomic dysfunction, was assessed using a heart rate monitor and computer. Blood pressure (BP) was measured using a random zero sphygmomanometer. Reduced PD was found in 14/129 (13.8%) children with DM and in 5.8% of the controls. The diabetic children with reduced PD had longer DM duration, higher HbA1c, raised diastolic BP and higher urinary A/C than those with normal PD. Fifty percent of these children also had increased A/C and impaired HRV, in addition to impaired PD. Another group of 25/129 (19.4%) children with DM presented intermittently raised mean urinary A/C, while five children presented persistently raised A/C in both 48-h urine collections. The characteristics which differentiated the microalbuminuric group from the normoalbuminuric one were older age, longer DM duration, poorer glycemic control, reduced PD, impaired HRV and raised diastolic BP. It seems that diabetic nephropathy (DN) and autonomic neuropathy (DAN) exist in concert in childhood DM. Diabetic children with impaired indices of DN and DAN are older, pubertal and have longer DM duration and higher HbA1c values than the rest of the diabetic population.

Adolescent↗

PubMed2001

Growth response, pubertal growth and final height in Greek children with growth hormone (GH) deficiency on long-term GH therapy and factors affecting outcome.

The growth data of 156 children (100 boys, 56 girls) with growth hormone deficiency (GHD), treated with human growth hormone (GH) for 5.7+/-3.7 years, from 1970-1997, were retrospectively analyzed to assess the efficacy of GH treatment and the factors involved. 62.2% of the studied population had idiopathic GHD (IGHD) and 35.2% had organic GHD (OGHD). At initiation of treatment, chronological age (CA) was 10.1+/-4.0 years in children with IGHD and 9.7+/-4.0 years in those with OGHD, while bone age (BA) was 7.0+/-3.7 and 7.7+/-3.2 years, respectively. The SDS of the growth velocity during the first year of therapy (GV1) was negatively related to CA at start of therapy (r = -0.53, p = 0.01). 109 children have reached final height (FH): 67 boys (FH = 165.3+/-6.3 cm) and 42 girls (FH = 153.9+/-5.4 cm). FH SDS was not significantly different from target height (TH) SDS. In the total group, FH SDS was positively related to height SDS for CA and BA at start of therapy (p = 0.01, p = 0.001, respectively), to TH SDS (r = 0.40, p = 0.001), and to GV1 (r = 0.33, p = 0.001). TH SDS was not different between the IGHD and OGHD groups (-1.02+/-0.8 vs. -0.94+/-6.9). The height gain at puberty did not differ between the groups with induced or spontaneous puberty in boys (23.7+/-8.6 vs. 25.4+/-6.9, not significant), while in girls it was higher in the group with spontaneous puberty (12.7+/-7.3 vs. 20.0+/-9.0, p = 0.008). The age and height at start of puberty was higher in girls and boys with induced puberty. In the total group, the FH SDS of children with induced puberty was higher in comparison with those with spontaneous puberty (-1.0+/-0.8 vs. -1.7+/-0.9, p = 0.001) and it was positively related to the height at start of puberty. When the two sexes were analyzed separately, the difference reached significance only in boys. In conclusion, children with GHD on GH treatment achieved a final height which was comparable to their genetic potential. The FH of children with OGHD was not different from those with IGHD. The age and height at start of puberty were the most significant determining factors for FH. Hence, a better FH might be expected by delaying or arresting puberty.

Adolescent↗

PubMed1997

Consistency of pupillary abnormality in children and adolescents with diabetes.

Repeat measurements on pupillary adaptation to darkness were performed in a cohort of 66 children and adolescents with insulin-dependent diabetes mellitus (IDDM) (initial age 6.9-17.0 years) after a mean interval of 3.5 years, using a portable pupillometer. While there was a close correlation between the results of the two studies (r = 0.94, p < 0.001), the pupillary dilatation, the ratio of the pupil diameter to the iris diameter % (PD%), had decreased significantly (61.5% vs 62.9%, p < 0.001) over these 3.5 years in children with diabetes. The same measurements were performed on 89 healthy control children in the first study and 66 in the reassessment period and PD% was not significantly different in the two control groups. Five children with diabetes identified as having abnormal pupillary dilatation in the first study were outside the normal range 3.5 years later. In addition 4 children in whom initial testing had been normal, showed abnormality at the time of the second study. None of these children had symptoms of autonomic neuropathy. These findings suggest that abnormality in pupillary adaptation in diabetic children is consistent and increases with time and may serve as an early marker of tissue damage associated with diabetes.

Adolescent↗

PubMed1996

Consistency of microvascular and autonomic abnormalities in diabetes.

The progression of early measures of microvascular disease and autonomic neuropathy were studied in a group of 81 children with insulin dependent diabetes mellitus over a mean interval of 4.2 years. Repeated measurements were made of blood pressure, albumin excretion, joint mobility, and pupillary dilatation in darkness. Over the years between the first and the second study, systolic and diastolic blood pressure showed positive tracking correlations (r = 0.38 and r = 0.32) with a small but significant deviation from normality; albumin/creatinine ratio was significantly increased (0.79 v 0.55); a greater number of children were identified in the second study as having limitation of mobility of the fifth metacarpophalangeal joint; and pupillary dilatation in darkness significantly decreased (61.5% v 62.9%); 62% of the children with one or more abnormal measurements in the first study were found to have measurements outside the normal ranges in the second study, indicating a consistency in observations over time. It remains to be seen with what accuracy these measurements predict adult onset clinical disease.

Adolescent↗

PubMed1995

Is microalbuminuria progressive?

In 1990, 81 children and adolescents with insulin dependent diabetes were studied for early signs of diabetic nephropathy. Nine patients were identified as having microalbuminuria (incipient nephropathy). These subjects were re-examined three years later. In five of these cases, the second examination revealed normal albumin excretion; in three of the four cases in whom microalbuminuria persisted, the rate of albumin excretion had decreased. The general improvement in albumin excretion rates in the initially microalbuminuric group could not be explained by improved glycaemic control nor interventional drug treatment. The lack of progression in this microalbuminuric group from the original prevalence study suggests that this method of identifying early nephropathy in childhood may not be valid or that the progression of incipient nephropathy in childhood is more irregular or slower than in later life.

Adolescent↗

PubMed1995

National data on the epidemiology of IDDM in Greece. Cases diagnosed in 1992. Hellenic Epidemiology Study Group.

OBJECTIVE: To detect the incidence, geographic distribution, and seasonal variation of insulin-dependent diabetes mellitus (IDDM) in all of Greece. RESEARCH DESIGN AND METHODS: One hundred and thirty-seven children (75 boys and 62 girls) up to 14.9 years of age were diagnosed with IDDM in Greece in 1992. RESULTS: The age-adjusted incidence of IDDM in Greece in 1992 was 6.25/100,000 population (boys: 6.17/100,000;: girls: 6.28/100,000). There was a significant pubertal peak. The incidence of IDDM was significantly higher in metropolitan (10.0/100,000) than in rural (4.21/100,000), semirural (7.48/100,000), or urban areas (5.36/100,000) of Athens. There was a marginal difference between rural and semirural areas. No significant seasonal variation in the incidence of IDDM was observed. CONCLUSIONS: We conclude that the incidence of IDDM in Greece is among the five lowest in Europe. An impressive clustering of cases was observed in the Athens metropolitan area compared with the rural and semirural areas, an observation that possibly underlines the importance of environmental factors (stressful situations, infections, dietary habits, and others) in the expression of IDDM.

Adolescent↗

PubMed1994

Pupil size in diabetes.

Sympathetic function was studied in 101 diabetic children and 102 age and sex matched control children, as part of a longitudinal study of the evolution of microvascular disease in the population of diabetic children and adolescents in Avon County. The median (range) age of the diabetic population was 13.5 (6.0-17.2) years, the duration of diabetes was 4.0 (0.4-13.9) years, and glycated haemoglobin (HbA1) was 10.9 (7.0-18.1)%. Pupillary adaptation in darkness, as an index of sympathetic neuropathy, was measured using a Polaroid portable pupillometer. Diabetic children had a significantly smaller median pupillary diameter, measured as the pupil/iris ratio and expressed as a percentage, than control children (median (range) 62.9 (50.3-72.1) v 65.9 (52.2-73.8)). Pupillary diameter was significantly related to diabetes duration (r = -0.22), HbA1 (r = -0.34), systolic blood pressure (r = -0.25), diastolic blood pressure (r = -0.49), and mean albumin/creatinine ratio on random urine samples (r = -0.26). Pupillary diameter was not related to age (r = -0.1). Eight (7.9%) diabetic and four (3.9%) control children were identified as having abnormal pupillary dilation in darkness. In comparison with the rest of the diabetic population, these diabetic children had longer diabetes duration and poorer glycaemic control. Polaroid pupillometry has demonstrated subclinical autonomic neuropathy in a population of diabetic children and adolescents. These abnormalities were related to poor metabolic control, long diabetes duration, and also to other indices of microvascular disease.

Adolescent↗

PubMedDate not supplied

Autonomic function in a cohort of children with diabetes.

129 diabetic children in Avon County participated in a longitudinal study of the evolution of microvascular disease together with 129 age- and sex-matched controls. Diabetic children had mean (+/- SD) age 12.7 (+/- 3.4) years (range: 3.7-16.8), mean (+/- SD) diabetes duration 3.9 (+/- 3.2) years (range: 0.1-13.4) and mean (+/- SD) HbA1 11.1% (+/- 2.2) (range: 6.5-18.2). Cardiovascular autonomic function was studied by four heart rate (HR) tests using a computerized system of HR monitoring. As a group, diabetic children had higher mean HR (p = 0.0004) and reduced max/min HR ratio while standing (p = 0.001), compared with the control children. HR ratio while standing was the only variable related to diabetes duration (r = -0.20, p = 0.018), while no correlation of HR variables with glycaemic control was found. Twenty diabetic children (15.5%) had one abnormal HR test. Ten diabetic children (7.7%) demonstrated abnormality in two or more HR tests. When compared with the other diabetic children in the cohort, these ten children were found to be younger in age (mean age: 9.4 vs 12.0 yr, p = 0.05), but did not otherwise differ in terms of diabetes duration or glycaemic control. No pubertal or sex effect in the development of diabetic autonomic neuropathy was detected. These findings suggest that autonomic function may be impaired early in childhood diabetes, independent of the duration of the disease or the quality of glycaemic control.

Adolescent↗

PubMedDate not supplied

Prevalence of microvascular and neurologic abnormalities in a population of diabetic children.

One hundred and twenty-nine (87%) of a total county population of 150 eligible diabetic children together with 144 age- and sex-matched control children participated in a longitudinal, epidemiological study of the evolution of diabetic microvascular disease. At enrollment the median (range) age of the diabetic children was 12.5 (3.7-16.8) years with a median diabetes duration of 2.9 (0.1-13.4) years and a median HbAl of 11.1 (6.8-17.9)%. Two sets of measurements were made over a period of 18 months for all indices of microvascular disease, while autonomic function was studied on one occasion. Urinary albumin excretion in diabetic children was assessed from all voidings during two timed 48-h urine collections and was expressed as urinary albumin/creatinine ratios (ACR). Blood pressure (BP) was measured using a random zero sphygmomanometer. Autonomic function was assessed by pupillary adaptation in darkness, using a portable Polaroid pupillometer, and by heart rate (HR) variation recorded by dedicated computer. Vibration sensation thresholds (VST) (as indices of peripheral neuropathy) were recorded using a Biothesiometer. Limited joint mobility (LJM) was assessed by the "prayer sign". Five (3.9%) diabetic children presented raised mean ACR in more than two of four 24-h urine collections. Fourteen (10.8%) diabetic children were identified as having persistently raised BP during both study periods. Impaired HR response in one HR test was observed in 20 (15.5%) diabetic children, while ten (7.7%) diabetic children demonstrated abnormalities in two or more HR tests. Reduced pupillary adaptation in darkness was found in eight (7.9%) diabetic children. Persistent vibration sensation impairment (VST) in lower limbs was detected in eight (6.2%) diabetic children, while LJM was present in 12 (9.3%) diabetic children. Eight of the 129 diabetic children (6.2%) were found to have abnormality in two and one in three indices of microvascular and autonomic function. Six of nine children had coexistence of impaired autonomic neuropathy and nephropathy. These nine children were diagnosed at a younger age than the rest of the diabetic population (5.1 vs 8.0 yr, p=0.002). Four of nine were aged >11 yr and five of nine had had diabetes for >5 yr. Thus, a constellation of microvascular and neurological abnormalities were demonstrable in a small proportion of diabetic children, who were younger than the rest of the population at the time of onset of their disease. Longitudinal study of this population will demonstrate the clinical significance of these findings.

Adaptation, Ocular↗