Continuous glucose monitor use in type 2 diabetes mellitus in pregnancy and perinatal outcomes: a systematic review and meta-analysis

OBJECTIVE

This study aimed to assess whether continuous glucose monitor use in type 2 diabetes mellitus in pregnancy is associated with improved perinatal outcomes.

DATA SOURCES

We searched Ovid MEDLINE, Scopus, ClinicalTrials.gov, and Cochrane library from inception through May 9, 2022.

STUDY ELIGIBILITY CRITERIA

We included all studies that compared continuous glucose monitor use with fingerstick glucose monitoring in women with type 2 diabetes mellitus.

METHODS

The initial search yielded 2463 unique citations that were screened in Covidence by 2 independent reviewers. Study types included randomized controlled trials, cohort studies, and cross-sectional studies. Our outcomes of interest were macrosomia or large-for-gestational-age infants, hemoglobin A1c, cesarean delivery, hypertensive disorders of pregnancy including preeclampsia, gestational age at delivery, and neonatal hypoglycemia.

RESULTS

Three randomized controlled trials met the inclusion criteria. We performed random-effects meta-analyses of estimates from 2 studies without risk of significant bias and reported summary adjusted odds ratios and 95% confidence intervals. Meta-analysis of 56 women with continuous glucose monitor use and 53 control women without continuous glucose monitor use showed that there was no difference in the incidence of large-for-gestational-age infants between continuous glucose monitor users and standard-of-care controls (odds ratio, 0.78; 95% confidence interval, 0.34-1.78) with an I2 of 0%. In addition, there was no difference in the development of preeclampsia between continuous glucose monitor users and standard-of-care controls (odds ratio, 1.63; 95% confidence interval, 0.34-7.22) with an I2 of 0%.

CONCLUSION

Continuous glucose monitor use was not associated with improved perinatal outcomes as assessed by large-for-gestational-age infants and preeclampsia. This review is limited by the small amount of data available for this population, and further research is needed.

Changes in brain dopamine receptors in MPTP parkinsonian monkeys following L-dopa treatment

Twenty-two monkeys (Macaca fascicularis) were utilized in this study. Ten animals were rendered parkinsonian with serial injections of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine). Five of these parkinsonian monkeys received L-dopa/carbidopa treatment, and five animals did not. The remaining twelve animals did not receive MPTP. Eight of these animals received no L-dopa treatment, two animals were treated chronically with L-dopa/carbidopa and two animals received L-dopa/carbidopa only on the day of sacrifice. All animals were given weekly scored neurologic examinations throughout the study. Their movement was quantitated in an activity box. All animals were sacrificed by an overdose of sodium pentobarbital. The parkinsonian animals were sacrificed 107-355 days after their last MPTP injection. The brains were removed and frozen. Punch samples were taken from the caudate and putamen for tissue dopamine determination. Selected areas of the basal ganglia were cut into 20 microns sections for quantitative receptor autoradiography. The density of D1 and D2 receptors was evaluated in the basal ganglia of these animals at the level of the anterior commissure. For the D2 assay, total binding was determined using various concentrations of [3H]spiperone in buffer containing 300 nm mianserin. For the D1 assay, total binding was determined using various concentrations of [3H]SCH-23390. Tissue isotope concentration was determined from the autoradiographs. The MPTP parkinsonian monkeys showed a mean striatal dopamine depletion of 93.5% and a mean clinical score of 9.0. The untreated parkinsonian monkeys demonstrated an increase in the number of D2 sites as compared to controls. This increase was greatest in the lateral putamen.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in brain catecholamines and dopamine uptake sites at different stages of MPTP parkinsonism in monkeys

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been shown to produce parkinsonism in primates. We have studied the changes in brain catecholamines and the distribution of desipramine insensitive mazindol binding sites in MPTP parkinsonian primates at different levels of parkinsonism. Thirty-seven monkeys (Macaca fascicularis) were utilized in this study. Twelve naive animals received no treatment and served as controls. Twenty-five animals were rendered parkinsonian with serial injections of MPTP. All animals were given scored neurologic examinations throughout the study. Their movement was quantitated in an activity box. The animals were sacrificed 30-360 days after their last MPTP injection. The clinical exam of the MPTP parkinsonian monkeys demonstrated mildly to severely affected animals. There was an exponential decrease in brain catecholamine levels with increased clinical parkinsonism. The MPTP parkinsonian animals showed the greatest decrease (67-99.8%) in tissue dopamine levels in the caudate nucleus. The putamen followed closely in severity (48-99.8%) and the nucleus accumbens was much less affected (0-40%). The percent reduction of norepinephrine in the anterior pole of the frontal cortex (0-48%) was similar in degree to the decreased dopamine levels in the nucleus accumbens. Mazindol binding was decreased 30-98% in the caudate nucleus, 20-97% in the putamen, 0-26% in the nucleus accumbens, 80-96% in the substantia nigra pars compacta and 49-94% in the ventral tegmental area. In the striatum, the decreased mazindol binding was more pronounced laterally and posteriorly. In each animal, there was good correlation between tissue dopamine levels and the number of mazindol binding sites.

Acetylcholinesterase and choline acetyltransferase staining of neurons in the opossum esophagus

The purpose of the present investigation was to identify and compare cholinergic intramural neurons in the lower esophageal sphincter and esophageal body by histochemical staining for acetylcholinesterase and the enzyme that synthesizes acetylcholine, choline acetyltransferase. Opossums were anesthetized and their abdominal cavity was opened by a midline incision to expose the esophagogastric junction. The lower esophageal sphincter was identified manometerically and localized in situ with markers. Tissues were removed, rapidly frozen in freon cooled with liquid nitrogen and serial cryostat sections were obtained from the lower esophageal sphincter and esophageal body. Sections were stained with one of the above histochemical procedures and adjacent sections were stained with Solachrome cyanin , which differentially stains nerve elements from muscle fibers. The muscle of the lower esophageal sphincter and esophageal body was stained with nonspecific cholinesterase with some selectivity of intensity of reaction in the various smooth muscle layers. All identifiable plexus neurons in the esophagus stained for nonspecific cholinesterase and acetylcholinesterase. Nerve fiber tracts were also stained for acetylcholinesterase within the longitudinal and circular layers of the tunica muscularis. Reaction for choline acetyltransferase showed no staining in the muscle layers or nerve fiber tracts of either part of the esophagus studied; however, selected neurons within the myenteric plexus of both regions (approximately 38%) were reactive. There was no significant difference in the number of positive choline acetyltransferase neurons in the lower esophageal sphincter or esophageal body.