Prevalence of Microvascular and Neurologic Abnormalities in a Population of Diabetic Children

Abstract

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.

Diabetic Autonomic Neuropathy

“…Diabetic patients with a history of poor glycemic control Long-term poor glycemic control can only increase the risk of developing advanced diabetic neuropathy, although long-term follow-up studies are lacking (117). Mustonen et al (173) showed in a 4-year follow-up study of 32 individuals with type 2 diabetes that poor glycemic control was an important determinant of the progression of autonomic nerve dysfunction.…”

Diabetic Cardiovascular Autonomic Neuropathy

“…49 -53 • Poor glycemic control plays a central role in development and progression. 49,54 • Intensive therapy can slow the progression and delay the appearance of abnormal autonomic function tests. 55 • Subclinical autonomic neuropathy can be detected early using autonomic function tests.…”

Diabetic neuropathy in children

“…Subsequent studies reported variable rates of DN among children with T1D, ranging from 22% (Kaar et al, 1983), 57% (Hyllienmark et al, 1995), 87% (Meh and Denislic, 1998), to 97% (Karsidag et al, 2005). The presence of diabetic autonomic neuropathy is likely underestimated owing to suboptimal screening, and subclinical diabetic autonomic neuropathy has been reported to be between 8% and 75% in children with T1D (Karavanaki and Baum, 1999;Verrotti et al, 2009) (see Table 10.2). DN is also an early complication of T2D (Karabouta et al, 2008); however, the prevalence data on neuropathy in pediatric T2D are currently limited.…”

“…Autonomic neuropathy may be present early in childhood (Lucini et al, 2009), independent of the duration of diabetes or the degree of glycemic control (Verrotti et al, 1995;Karavanaki and Baum, 1999). In studies using pupillary constriction as a marker of autonomic function, Schwingshandl found that 142 adolescents with T1D had smaller resting pupil diameter than 75 controls; abnormal pupillary response correlated with higher hemoglobin AIc (HbA1c), longer duration of diabetes, and presence of diabetic retinopathy (Schwingshandl et al, 1993).…”