Decreased nocturnal glucose variability in non-diabetic patients with sleep apnea: a pilot study

BACKGROUND

Obstructive sleep apnea has been sho be associated with impaired glucose metabolism and overt diabetes mellitus. However, the effect of hypoxic episodes on nocturnal glucose regulation in non-diabetic patients is unknown.

OBJECTIVES

To investigate the effect of hypoxemia and nocturnal glucose homeosatsis in non-diabetic patients with sleep apnea.

METHODS

Seven non-diabetic patients with moderate to severe sleep apnea were connected to a continuous glucose-monitoring sensor while undergoing overnight polysomnography. Mean SpO2 and percentage of time spent at SpO2 90% were recorded. The correlation between mean glucose levels, the difference between consecutive mean glucose measurements (glucose variability) and the corresponding oxygen saturation variables were determined in each patient during REM and non-REM sleep.

RESULTS

No consistent correlation was found forthe individual patient between oxygen saturation variables and glucose levels during sleep. However, a lower mean SpO2 correlated with decreased glucose variability during sleep (r = 0.79, P = 0.034). This effect was primarily evident during REM sleep in patients with significant, compared to those with mild, oxygen desaturations during sleep (> 30% vs. < 10% of sleeping tim spent with SpO2 < 90%) (P = 0.03).

CONCLUSIONS

Severe nocturnal hypoxemia in non-diabetic patients with moderate to severe sleep apnea might affect glucose regulation primarily during REM sleep.

Mislabelled cow's milk allergy in infants: a prospective cohort study

BACKGROUND

Although cow's milk allergy (CMA) is one of the most common food allergies, mislabelling non-allergic infants as being allergic to cow's milk is more common. Despite this, characteristics of families and infants with mislabelled CMA are lacking.

METHODS

Using a prospective population-based study, we identified infants with any possible adverse reaction to cow's milk (n=381) from a cohort of 13 019 infants followed from birth. They had a detailed history taken, skin prick tests and an oral food challenge when indicated. Infants with symptoms for which the causative relationship to cow's milk protein was excluded were compared with infants with IgE-mediated CMA and with a control group, and followed for 2-5 years.

RESULTS

Overall, 243 infants (1.87%) with mislabelled CMA were identified. Compared with 66 infants with IgE-mediated CMA, those with mislabelled CMA presented earlier and with symptoms usually involving a single organ system. Doctor-diagnosed atopic dermatitis (AD) was associated with mislabelled CMA (p<0.001), manifested primarily as skin rashes, compared with control infants. Higher maternal and paternal education were also associated with mislabelled CMA (p=0.007 and p=0.035, respectively) and manifested primarily as non-specific symptoms.

CONCLUSIONS

Mislabelled CMA typically presents within the first 3 months of life involving a single organ. Infant AD and higher parental academic education are associated with mislabelled reactions. Better parental and physician awareness of the importance of objectively diagnosing milk allergy is required to avoid mislabelling of infants as being allergic to cow's milk and to prevent potential nutritional deficiencies.

Airway inflammation in cystic fibrosis: molecular mechanisms and clinical implications

Airway epithelial cells and immune cells participate in the inflammatory process responsible for much of the pathology found in the lung of patients with cystic fibrosis (CF). Intense bronchial neutrophilic inflammation and release of proteases and oxygen radicals perpetuate the vicious cycle and progressively damage the airways. In vitro studies suggest that CF transmembrane conductance regulator (CFTR)-deficient airway epithelial cells display signalling abnormalities and aberrant intracellular processes which lead to transcription of inflammatory mediators. Several transcription factors, especially nuclear factor-κB, are activated. In addition, the accumulation of abnormally processed CFTR in the endoplasmic reticulum results in unfolded protein responses that trigger 'cell stress' and apoptosis leading to dysregulation of the epithelial cells and innate immune function in the lung, resulting in exaggerated and ineffective airway inflammation. Measuring airway inflammation is crucial for initiating treatment and monitoring its effect. No inflammatory biomarker predictive for the clinical course of CF lung disease is currently known, although neutrophil elastase seems to correlate with lung function decline. CF animal models mimicking human lung disease may provide an important insight into the pathogenesis of lung inflammation in CF and identify new therapeutic targets.

Hepatitis among psychiatric inpatients: a high-risk group?

Viral hepatitis B (HBV) and C (HCV) have been reported to be prevalent among residents of custodial institutions and health-care workers. Among psychiatric inpatients sparse research was undertaken and results are controversial. We designed the present study to evaluate rates of HBV and HCV among psychiatric inpatients and to characterize the "typical" carriers. All newly admitted patients to the Y. Abarbanel Mental Health Center who were judged by the admitting psychiatrist to be at high-risk underwent laboratory tests for acute and chronic HBV and/or HCV. The period covered in the present study was from January 1993 to December 1995. Inclusion in the high-risk group was based on one (or more) of the following: history of blood transfusion; I.V. drug abuse; homosexuality; promiscuous sexuality; prostitution; positive HIV test. Of 1327 newly admitted patients, 121 (9.1%) were clinically judged to be at risk. Of these 42 (34.7%) were positive for HBV (37/42) or HCV (5/42). The mean age among infected patients was 37.1+11.6 years; the majority were males (30/42) and the most frequent psychiatric illness was schizophrenia (24/42). In more than half (26/42) of the infected patients the clinical judgement of risk was promiscuous sexuality.Although as a group psychiatric patients newly admitted for treatment do not seem to constitute high risk for HBC and/or HCV carries, sexual promiscuosity should prompt psychiatrists to test for possible hepatitis infections in order to reduce risk to other inpatients and staff.

Role of parental atopy in cow's milk allergy: a population-based study

BACKGROUND

A family history of atopy has been considered an independent risk factor for atopic diseases in children.

OBJECTIVE

To relate the risk of an infant developing IgE-mediated cow's milk allergy (IgE-CMA) to the atopic status of parents.

METHODS

Assessment of the parental atopic status of children with IgE-CMA (n = 66) previously identified in a large-scale prospective study was compared with the parental atopic status of a control group of healthy infants (n = 156). The atopic status was identified both by self-reporting and skin prick tests (SPTs).

RESULTS

Analysis for the risk for infants to develop IgE-CMA depended on the assessment method used. No significant differences were noted in self-reported parental atopic status between the IgE-CMA patients and the control group. However, among the subgroup of infants with persistent IgE-CMA (n = 25), maternal but not paternal self-reporting for atopy was more likely compared with parents of the control group (P = .04). In contrast, when analyzed by SPT, in both this persistent subgroup and the total allergic cohort, no significant differences were noted whether analyzed by single parent or both parents and whether the parent tested singly or multiply positive on the SPT.

CONCLUSION

In families with children with persistent IgE-CMA, self-reporting of atopy by parents may be biased. Furthermore, the demonstration of IgE-mediated responses to allergens in parents is insufficient by itself, in a general population cohort, to predict which infants are at greatest risk of developing IgE-CMA.

In silico analysis of the regulatory region of the Yellowtail Kingfish and Zebrafish Kiss and Kiss receptor genes

We have cloned and analysed the partial putative promoter sequences of the Yellowtail Kingfish (Seriola lalandi) Kiss2 and Kiss2r genes (380 and 420 bp, respectively). We obtained in silico 1.5 kb of the zebrafish (Danio rerio) Kiss1, Kiss2, Kiss1r and zfKiss2r sequences upstream of the putative transcriptional initiation site. Bioinformatic analysis revealed promoter regulatory elements including AP-1, Sp1, GR, ER, PR, AR, GATA-1, TTF-1, YY1 and C/EBP. These regulatory elements may mediate novel roles of the Kiss genes and their receptors in addition to their established role in reproductive function.

Cow's milk associated rectal bleeding: a population based prospective study

BACKGROUND

Isolated rectal bleeding in infants is often attributed to the consumption of cow's milk. However, the prevalence of this condition has not been described, and its preferred diagnostic methods and management are controversial.

METHODS

In a prospective population-based study following 13,019 children from birth, 21 infants with isolated rectal bleeding attributed to cow's milk protein consumption were identified. Following evaluation, parents were encouraged to resume cow's milk protein and infants were followed for reappearance of symptoms and thereafter for 6 yr. In addition, infants with rectal bleeding were compared to a control group of healthy infants.

RESULTS

The prevalence of isolated rectal bleeding attributed to cow's milk consumption was 0.16%. All infants were asymptomatic within days of dietary modifications. Eleven of the 14 infants (78.5%) whose parents reintroduced cow's milk protein to their diet following our evaluation tolerated it with no adverse effects. Those 11 infants were significantly younger at initial consumption of cow's milk protein (6.7 ± 1.6 months) compared to those who continued elimination diet (17.7 ± 9.2 months), (p = 0.002) while their 1-yr hemoglobin levels were comparable (p = 0.98). No risk factors for rectal bleeding were identified.

CONCLUSIONS

The prevalence of isolated rectal bleeding attributed to cow' milk is low. The condition is generally benign and resolves quickly with elimination diet. Reintroduction of cow's milk following resolution of symptoms is often well tolerated and is recommended for confirming the diagnosis and avoiding prolonged unnecessary elimination diets.

The Kiss2 receptor (Kiss2r) gene in Southern Bluefin Tuna, Thunnus maccoyii and in Yellowtail Kingfish, Seriola lalandi - functional analysis and isolation of transcript variants

The kisspeptin system plays an essential role in reproductive function in vertebrates, particularly in the onset of puberty. We investigated the kisspeptin system in two Perciform teleosts, the Southern Bluefin Tuna (SBT; Thunnus maccoyii), and the Yellowtail Kingfish (YTK; Seriola lalandi), by characterising their kisspeptin 2 receptor (Kiss2r) genes. In addition to the full length Kiss2r cDNA sequences, we have isolated from SBT and YTK a transcript variant that retained an intron. We have further obtained three ytkKiss2r transcript variants that contained deletions. In vitro functional analysis of the full length SBT and YTK Kiss2r showed higher response to Kiss2-10 than to Kiss1-10, with stronger transduction via PKC than PKA. The full length ytkKiss2r and two deletion variants were differentially expressed in the brain of male, but not in female, juvenile YTK treated with increasing doses of Kiss2-10 peptide. In the gonads, the expression level of the ytkKiss2r transcripts did not vary significantly either in the male or female fish. This is the first time that transcript variants of the Kiss2r gene that contain deletions and show responsiveness to treatments with kisspeptin have been reported in any teleost.

Natural course and risk factors for persistence of IgE-mediated cow's milk allergy

OBJECTIVE

To describe the natural course of IgE-mediated cow's milk allergy (IgE-CMA) and to determine risk factors for its persistence in a population-based cohort.

STUDY DESIGN

In a prospective cohort study, 54 infants with IgE-CMA were identified from a population of 13 019 children followed from birth. Diagnosis of IgE-CMA was based on history, skin prick test (SPT), and an oral food challenge (OFC) when indicated. Allergic infants were followed for 48-60 months. Families were contacted by telephone every 6 months and asked about recent exposures to milk. OFC was repeated to evaluate for recovery. Clinical characteristics, SPT, and OFC outcomes were compared between infants with persistent IgE-CMA and infants who recovered.

RESULTS

Thirty-one infants (57.4%) recovered from IgE-CMA during the study period. Most infants (70.9%) recovered within the first 2 years. Risk factors for persistence on multivariate analysis included a reaction to <10 mL of milk on OFC (or on first exposure as estimated by the guardian, if OFC was not performed) (P = .01), a larger wheal size on SPT (P = .014), and age of ≤30 days at time of first reaction (P = .05).

CONCLUSIONS

Resolution occurs in most infants with IgE-CMA. Infants reacting to <10 mL of milk or in the first month of life, and those with a larger wheal size on SPT, are at increased risk for persistence.

Hypoxemia correlates with attentional dysfunction in patients with obstructive sleep apnea

PURPOSE

Obstructive sleep apnea is associated with cognitive impairment, but whether hypoxemia or repeated arousals and sleepiness are the underlying mechanism is controversial. Studies using a wide range of attention and executive functions tests in patients with severe sleep apnea are lacking.

METHODS

In a prospective cohort study, 40 patients aged 30-70 years, diagnosed with obstructive sleep apnea (apnea-hypopnea index ≥5) were recruited. Patients with known cardiovascular, pulmonary, psychiatric, or neurological disease, and or patients receiving anti-psychotic, sedatives, or stimulant medications were excluded. Patients underwent full overnight polysomnography including continuous oxygen saturation measurements followed by extensive neuropsychological testings in attention and executive function domains. The correlation between sleep apnea severity and patients' performance on the neuropsychological tests was examined.

RESULTS

The patients' performance on measures of attention and executive function was significantly worse compared to the average in a normal population. Attention, as reflected by the number of omissions and by the reaction time on the Conners' Continuous Performance Test correlated significantly with the apnea-hypopnea index (r = 0.6, p < 0.001 and r = 0.48, p = 0.003, respectively) and with parameters of hypoxemia, namely the average SpO(2) (r = -0.51, p = 0.002 and r = -0.39, p = 0.02, respectively) and the percent time spent with SpO(2) < 90% (r = 0.57, p < 0.001 and r = 0.39, p = 0.02, respectively), but not with the degree of sleepiness. Executive dysfunction did not correlate with sleep parameters.

DISCUSSION

Attention is the predominant cognitive function affected in patients with obstructive sleep apnea and correlates primarily with nocturnal hypoxemia rather than daytime sleepiness or sleep fragmentation. Executive functions, while below average in some patients, do not correlate with polysomnographic parameters.

Management of primary spontaneous pneumothorax in children

OBJECTIVE

To examine the role of CT scans and early surgical intervention in the management of pediatric patients with primary spontaneous pneumothorax (PSP).

METHODS

Retrospective cohort study.

RESULTS

The authors identified 46 cases with 70 episodes of pneumothorax. The recurrence rate among conservatively treated patients was 50% both after the first and the subsequent episode. Recurrence rate in cases with and without blebs on CT was comparable. Initial episodes were treated with supplemental oxygen (n = 18) and chest tube drainage (n = 18), and 10 patients underwent video-assisted thoracoscopic surgery (VATS). The recurrence rate was significantly lower following surgical intervention compared with other therapy, and morbidity was comparable with that in patients who needed chest tube drainage.

CONCLUSIONS

Recurrence after the first episode of PSP in children is frequent and is difficult to predict by CT findings. VATS is safe and effective in preventing recurrences. Surgical intervention may be an attractive alternative in patients who require chest tube drainage for the first episode of PSP.

Normal and elevated HbA1C levels correlate with severity of hypoxemia in patients with obstructive sleep apnea and decrease following CPAP treatment

PURPOSE

Sleep apnea is associated with higher HbA1C levels in patients with and without diabetes but whether its severity correlates with HbA1C levels ranging from normal to abnormal is less clear. Also, the effect of continuous positive airway pressure (CPAP) treatment on HbA1C levels in patients with sleep apnea is controversial.

METHODS

Thirty consecutive patients with obstructive sleep apnea were studied. None of the patients was previously diagnosed with diabetes. All patients underwent overnight polysomnography and HbA1C levels were determined. Patients were subdivided into three groups according to their HbA1C levels: <6% (n = 10), 6-6.5% (n = 10), and ≥6.5% (n = 10). Polysomnography and determination of HbA1C level were repeated in patients with severe sleep apnea (n = 12) following 3-5 months of CPAP treatment.

RESULTS

HbA1C levels across the spectrum from normal to abnormal correlated with severity of hypoxemia (average SpO(2), r = -0.43, p = 0.019 and percent time with SpO(2) < 90%, r = 0.48, p = 0.007). HbA1C levels decreased from a mean of 6.47 ± 0.67% to a mean of 6.28 ± 0.51%, p = 0.038 in 12 patients with severe sleep apnea following 3-5 months of CPAP treatment.

CONCLUSIONS

The severity of hypoxemia in patients with sleep apnea correlates with HbA1C levels ranging from normal to pre-diabetes and diabetes. CPAP treatment for 3-5 months decreases HbA1C levels in patients with severe sleep apnea.