The puzzle of metabolic effects of obstructive sleep apnoea in children

Does drug induced sleep endoscopy-directed surgery improve polysomnography measures in children with Down Syndrome and obstructive sleep apnea?

BACKGROUND

Children with Down Syndrome (DS) and obstructive sleep apnea (OSA) are difficult to treat, as first line therapies may not lead to significant improvement. Drug-induced sleep endoscopy (DISE) directed surgery may be particularly beneficial for these patients.

OBJECTIVE

To assess change in polysomnography (PSG) measures of patients with DS who underwent DISE-directed surgery.

METHODS

Retrospective chart review was performed on patients with DS who underwent DISE-directed surgery and had pre- and post-surgery PSG. Patients were analyzed in groups defined by previous adenotonsillectomy. Two-sided t-tests with equal variances were used to assess statistical significance.

RESULTS

Of 24 patients reviewed, 14 were surgically naïve and 10 had undergone prior adenotonsillectomy. The primary outcome was change in PSG parameters including apnea hypopnea index, obstructive apnea hypopnea index, oxygen nadir, oxygen desaturation index, and mean carbon dioxide level. While improvement was seen in all PSG parameters, only improvement in oxygen nadir in children who had undergone prior adenotonsillectomy was statistically significant (88.5% to 90.9%, p = .04).

CONCLUSIONS AND SIGNIFICANCE

DISE-directed surgery may be beneficial for children with DS and OSA, with improvement in the means of main PSG measures observed. A larger, prospective study is warranted to further explore DISE utility.

Circulating branched-chain amino acids in children with obstructive sleep apnea

INTRODUCTION

The effects of obstructive sleep apnea (OSA) on the metabolic system are not well understood, especially in children. Recent studies have provided evidence of the modulation of insulin action by branched-chain amino acids (BCAAs) and suggested novel mechanistic relationships between glucose and amino acid metabolic pathways. We hypothesized that plasma BCAA levels may serve as biomarkers of insulin resistance and metabolic dysfunction in children with OSA.

METHODS

A polysomnography was conducted for the diagnosis of OSA in 90 snoring children, in a tertiary hospital. Anthropometric and clinical data were measured and venous blood samples were collected for the measurement of plasma glucose, insulin, HbA1c, and amino acids.

RESULTS

Children with OSA had significantly higher levels of BCAAs (leucine, isoleucine, and total BCAAs) compared with those without OSA (P = 0.024). A positive significant correlation was observed between insulin levels and both leucine and isoleucine (r = 0.232; P < 0.05). On multivariate regression analyses, the presence of OSA was significantly associated with leucine, isoleucine, and total BCAA concentrations (P = 0.028), whereas the arousal index was associated with leucine, valine, and total BCAA levels (P = 0.037).

CONCLUSIONS

The presence of OSA and sleep fragmentation may induce changes in branched-chain amino acid metabolism in snoring children, independently of obesity. These data may suggest a new mechanism linking OSA and glucose homeostasis.