Scintigraphy using I-123-metaiodobenzylguanidine (I-123-MIBG) and Tc-99m-methoxyisobutylisonitrile (Tc-99m-MIBI) allows assessment of the cardiac sympathetic innervation and the myocardial perfusion. To investigate the natural history of cardiac sympathetic denervation in long-term diabetic patients without myocardial perfusion defects, global and regional I-123-MIBG and Tc-99m-MIBI uptake was determined (score 1-6; 1 = normal uptake, 6 = no uptake) in 22 patients with insulin-dependent (type I) diabetes mellitus (IDDM) at 3-year follow-up. All patients were treated with intensive insulin therapy and HbA1c was 8.0% +/- 1.0% at entry compared with 7.9% +/- 1.1% at follow-up. Cardiac sympathetic denervation (I-123-MIBG uptake score > 2), initially observed in 18 patients, was detectable in 21 patients at follow-up. The global myocardial I-123-MIBG uptake score deteriorated in eight patients, remained unchanged in 11 and improved in three patients. The changes in mean global I-123-MIBG uptake score (3.5 +/- 1.0 versus 3.8 +/- 0.8) were not significant. Reduction of the anterior, lateral, posterior, septal, and apical I-123-MIBG uptake did not progress significantly during follow-up. The mean uptake score of the posterior myocardial region (4.7 +/- 0.8) was smaller than the uptake score of the anterior (3.0 +/- 1.1, p = 0.001), lateral (3.2 +/- 0.9, p < 0.001) and septal (4.1 +/- 1.1, p < 0.05) myocardial regions. At follow-up, moderate myocardial perfusion defects (global Tc-99m-MIBI uptake score = 3) were detectable in four patients. Our study demonstrates that scintigraphically assessed cardiac sympathetic denervation does neither significantly regress nor progress on the average in a group of long-term IDDM patients during a 3-year follow-up. Thus, it is concluded that cardiac sympathetic abnormalities are a persistent, yet frequent phenomenon in long-term IDDM patients.

3-Iodobenzylguanidine↗

PubMedDate not supplied

Clinical utility of nonenzymatically glycosylated blood proteins as an index of glucose control.

This study compares the utility of nonenzymatically glycosylated serum proteins (lys-GSP) to glycosylated hemoglobins (HbA1a-c) as control indices of glucose homeostasis in patients with IDDM. The diagnostic value of lys-GSP was also examined in patients with non-insulin-dependent diabetes mellitus, in subjects with impaired glucose tolerance, and in two patients with insulinoma. The intraindividual fluctuation of lys-GSP in normoglycemic subjects is very small, resulting in an interindividual range of 3.0 +/- 0.3 lysine-bound glucose/mg protein (means +/- SD, N = 52). HbA1a-c with a normal range of 6.4 +/- 0.9% (N = 52) shows greater variability. In IDDM there is no overlap of lys-GSP levels between the normal and the diabetic range at the 95% confidence level. In patients treated with an open-loop insulin delivery system failure of normalization of the glucose balance was clearly discernible by an elevation of GSP. In contrast, in about 40% of the patients with incomplete glycemic control the HbA1a-c levels fell within the normal range. The utility of lys-GSP for diagnosis of diabetes is compared with the results of 60 oral glucose tolerance tests. Two patients suffering from insulinoma displayed decreased lys-GSP values. From these results it appears that determination of lys-GSP represents a more sensitive parameter for long-term control than HbA1a-c and is suitable for monitoring even small fluctuations of blood glucose.

Adolescent↗

PubMedDate not supplied

Orocaecal transit, bacterial overgrowth and hydrogen production in diabetes mellitus.

Orocaecal transit time was investigated using the hydrogen breath test in 39 insulin-requiring patients with long-standing Type I diabetes mellitus and 26 healthy control subjects. Thirty four patients complained of different gastrointestinal symptoms. The standard meal consisted of 10 g lactulose in 150 ml tap water. Mean transit time was significantly longer in the patient group (106.4 +/- 31.1 min) than in control subjects (84.2 +/- 27.1 min), and differences in OCTT between symptomatic subgroups were also significant. No correlation was found between orocaecal transit time and gastric emptying of a solid meal measured with scintigraphic method, HbA1c values, and other signs of automatic and peripheral neuropathy. The incidence of bacterial overgrowth among the diabetics was minimal. The percentage of H2 non-producers did not significantly differ between control and patient groups (23% and 26%, respectively). The absolute amount of breathed hydrogen was, however, significantly lower in diabetics at all time intervals. This indicates that specific changes in hydrogen production may be related to pathophysiological features as a consequence or as an associated symptom.

Adult↗

PubMedDate not supplied

Orocaecal transit-time by the H2 method: effects of definitions of caecal entry and test meal.

The study compares common variants of the hydrogen breath test to measure oroceacal transit time under different conditions. Definition of caecal entry point rather than procedural parameters were found to be a main variable influencing the test results. Visual assessment still seemed to be the most reliable and valid technique. To overcome its subjectivity and evaluator-dependency, a comprehensive set of rules simulating implicit criteria of expert physicians was defined and compared with commonly used caecal entry assessment rules. Results indicated that: 1) using visual assessment, experts produce highly consistent CE points; 2) caecal entries by the new rule set correlate highly with them, while previously published caecal entry detection methods were poorly correlated with visual assessment; 3) using a semiliquid test meal reduced reliability of all methods, but the new method remained superior; 4) earlier caecal entry detection methods failed completely when early peaks or baseline fluctuations were present; 5) detection of H2 non-producers and of bacterial overgrowth was much more difficult with classical caecal entry definitions than with the new rule-set.

Adolescent↗