Overlap syndrome: an indication for sleep studies? : A pilot study.

BACKGROUND: The coexistence of obstructive sleep apnea (OSA) and chronic obstructive pulmonary diseases (COPD) is known as overlap syndrome (OS); it occurs in 10-20% of patients with OSA. Patients with OS have a higher risk of pulmonary hypertension and worse nocturnal hypoxemia than those with either disease alone. Differences may be seen according to severity of COPD, anthropometric measures, and polysomnography (PSG) features of patients. Recent studies have suggested that long-term use of continuous positive airway pressure for OSA is associated with worsening of coexistent COPD. This stresses the importance of identifying this subgroup of patients in order to provide adequate therapy. OBJECTIVES: This study aims to describe the presence of OS among subjects at our institution and study its association to daytime hypercapnia, nocturnal hypoxemia, and severity of OSA and of COPD. METHODS: We reviewed the records of patients who underwent PSG and pulmonary function test (PFT) at our center since 2002. Data gathered from PSG and PFTs included respiratory disturbance index (RDI), apnea index, lowest nocturnal desaturation, forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity ratio, arterial blood gasses, and anthropometric measures. RESULTS: Five hundred forty-seven records were reviewed, but only 73 met all inclusion criteria for analysis. Thirty-six patients had COPD, 52 had OSA, and 29 had OS. The mean predicted FEV1 percent of all subjects was 80%, and the mean diurnal partial pressure of carbon dioxide (pCO(2)) was 39 mmHg. There were no significant differences in average pCO(2) or RDI between subjects with OSA and OS. In all subjects, hypercapnia significantly correlated with worse RDI (p = 0.01) and with worse nocturnal desaturation (p = 0.01). During rapid eye movement (REM) sleep, those with FEV1 less than 80% predicted had higher RDI than those with higher FEV1 (p = 0.010). CONCLUSION: In these preliminary results, the prevalence of OS in our population is similar to that previously reported. Daytime hypercapnia correlated with the more severe sleep-disordered breathing (SDB) and worse nocturnal hypoxemia in all subjects. Severity of obstructive ventilatory impairment is associated with worse SDB during REM sleep. Randomized trials to determine if PSGs are indicated in all patients with severe COPD should be considered. This is an ongoing study.

Prevalence and risk factors for sleep disordered breathing in a Puerto Rican middle-aged population.

BACKGROUND: The Berlin Questionnaire [an outcome of a primary care physicians' conference held in Berlin, Germany, in 1996 that was created to identify patients at high risk for sleep disordered breathing (SDB)] was administered to a representative sample of middle-age population in Puerto Rico in order to document the prevalence of SDB and its associated risk factors. MATERIALS AND METHODS: The island was divided in six regions to maintain heterogeneity and to have a representative sample of the population per region. Puerto Rican subjects between 30-60 years old were recruited in shopping malls, and questionnaires were filled. For each subject, body weight, neck circumference, and height were measured. Information regarding the diagnosis of hypertension was based upon a positive or negative response from study subject in a questionnaire. Data was collected for 6 months. RESULTS: A total of 290 subjects, all of Puerto Rican origin, were interviewed. Fifty-eight percent of the evaluated sample was found at high risk of SDB. Being male, hypertensive, and obese were the strongest risk factors for the development of SDB. In women, a neck size above 15 cm was a significant risk factor. CONCLUSIONS: This is the first time a prevalence study for SDB is done among a representative sample of subjects of Puerto Rican origin. It is the first step in documenting how SDB affects this ethnic group.

ORMDL3 gene is associated with asthma in three ethnically diverse populations.

RATIONALE: Independent replication of genetic associations in complex diseases, particularly in whole-genome association studies, is critical to confirm the association. OBJECTIVES: A whole-genome association study identified ORMDL3 as a promising candidate gene for asthma in white populations. Here, we attempted to confirm the role of ORMDL3 genetic variants in asthma in three ethnically diverse populations: Mexican, Puerto Rican, and African American. METHODS: We used family-based analyses to test for association between seven candidate single-nucleotide polymorphisms (SNPs) in and around the ORMDL3 gene and asthma and related phenotypes in 701 Puerto Rican and Mexican parent-child trios. We also evaluated these seven SNPs and an additional ORMDL3 SNP in 264 African American subjects with asthma and 176 healthy control subjects. MEASUREMENTS AND MAIN RESULTS: We found significant associations between two SNPs within ORMDL3 (rs4378650 and rs12603332) and asthma in Mexicans and African Americans (P = 0.028 and 0.001 for rs4378650 and P = 0.021 and 0.001 for rs12603332, respectively), and a trend toward association in Puerto Ricans (P = 0.076 and 0.080 for SNPs rs4378650 and rs12603332, respectively). These associations became stronger among Mexican and Puerto Rican subjects with asthma with IgE levels greater than 100 IU/ml. We did not find any association between ORMDL3 SNPs and baseline lung function or response to the bronchodilator albuterol. CONCLUSIONS: Our results confirm that the ORMDL3 locus is a risk factor for asthma in ethnically diverse populations. However, inconsistent SNP-level results suggest that further studies will be needed to determine the mechanism by which ORMDL3 predisposes to asthma.

Hepatopulmonary syndrome.

This is a report of a 56-year-old male who was admitted to the Intensive Care Unit of the San Juan V.A. Medical Center with altered mental status and severe hypoxemia. He was diagnosed with severe hyponatremia and hepatopulmonary syndrome.

The veteran population: one at high risk for sleep-disordered breathing.

Sleep complaints are very common among the general population and are usually accompanied by significant medical, psychological and social disturbances (Redline S, Strohl K, Otolaryngol Clin North Am, 132:303, 1999). A higher prevalence of sleep complaints has been described in the elderly (Vgontzas AN, Kales A, Annu Rev Med, 50:387-400, 1999). It is manifested by breathing disturbances during sleep, loud snoring, difficulties maintaining sleep, fatigue, daytime sleepiness, mood effects and impairment of daily activities (Lugaresi E, Cirignotta F, Zucconi M et al., Good and poor sleepers: an epidemiological survey of the San Marino population, Raven, New York, pp 1-12, 1983; Kales A, Soldatos CR, Kales JD, Am Fam Physician, 22:101-108, 1980). It has been associated with cardiovascular, endocrine and neurocognitive manifestations. Growing interest in early diagnosis and treatment has been noted in recent years based on emerging knowledge about the potential health consequences when the disease goes untreated (Nanen AM, Dunagan DP, Fleisher A et al., Chest, 121:1741, 2002). The veteran population in the mainland has a higher tendency for obesity, high blood pressure (HBP), sleep disorders and chronic alcohol consumption (Mustafa M, Erokwu N, Ebose I, Strohl K, Sleep Breath, 9:57-63, 2005). The Hispanic veteran population has never been studied in detail for sleep disorders and related conditions. We used previously validated screening tools for sleep disturbance breathing. Two hundred and forty-five questionnaires were administered. We found a higher prevalence of Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) in our population compared with data from the mainland (USA). The mean age was 64 years (+/-11). Ninety seven per cent were males. The mean body mass index was 25 kg/cm(2); mean Epworth Sleepiness Scale score was 8. Thirty-four per cent met high-risk criteria for sleep apnea, 53% for insomnia, 13% for symptoms suggestive of narcolepsy and 13% for those suggestive of restless leg syndrome. There were high incidences of alcohol consumption (37.6%), diabetes (32.7%), hypercholesterolemia (31.8%), depression (31.8%), hypertension (39.6%) and post-traumatic stress disorder (PTSD) (9.8%).

Ludwig's angina: an uncommon cause of chest pain.

A 71-year-old male with coronary artery disease, hypertension, diabetes mellitus, tobacco and opioid dependence came to the emergency room complaining of one episode of retrosternal chest pain oppressive in nature of one day of evolution. He had acute respiratory distress and required mechanical ventilation. The initial impression was myocardial ischemia, but electrocardiography and cardiac enzymes ruled it out. During the following hours, neck and tongue edema developed. He was started on broad-spectrum antibiotics empirically. Neck computed tomography scan revealed a left parapharyngeal and submandibular abscess. The abscess was drained. The source of infection was found on the second molar of the left lower jaw. The patient improved and was successfully weaned from mechanical ventilation. Despite advances in therapy, Ludwig's angina remains a potentially lethal infection in which early recognition plays a crucial role.

Genetic admixture and asthma-related phenotypes in Mexican American and Puerto Rican asthmatics.

Genetic association studies in admixed populations may be biased if individual ancestry varies within the population and the phenotype of interest is associated with ancestry. However, recently admixed populations also offer potential benefits in association studies since markers informative for ancestry may be in linkage disequilibrium across large distances. In particular, the enhanced LD in admixed populations may be used to identify alleles that underlie a genetically determined difference in a phenotype between two ancestral populations. Asthma is known to have different prevalence and severity among ancestrally distinct populations. We investigated several asthma-related phenotypes in two ancestrally admixed populations: Mexican Americans and Puerto Ricans. We used ancestry informative markers to estimate the individual ancestry of 181 Mexican American asthmatics and 181 Puerto Rican asthmatics and tested whether individual ancestry is associated with any of these phenotypes independently of known environmental factors. We found an association between higher European ancestry and more severe asthma as measured by both forced expiratory volume at 1 second (r=-0.21, p=0.005) and by a clinical assessment of severity among Mexican Americans (OR: 1.55; 95% CI 1.25 to 1.93). We found no significant associations between ancestry and severity or drug responsiveness among Puerto Ricans. These results suggest that asthma severity may be influenced by genetic factors differentiating Europeans and Native Americans in Mexican Americans, although differing results for Puerto Ricans require further investigation.

Parent-reported asthma in Puerto Rican children.

We conducted a survey to determine parent-reported asthma prevalence, morbidity, and healthcare utilization among 3527 children attending public schools (n = 2849) and private schools (n = 678) in San Juan, Puerto Rico. Schools were randomly selected from each of 12 geographic regions of the San Juan metropolitan area. Parents of children age 4-7 years old completed a 12-item questionnaire on asthma diagnosis, respiratory symptoms and morbidity, and healthcare utilization. Parents of children in public schools and private schools reported similar rates of a physician having previously diagnosed asthma in their children (43.2% vs. 39.4%); however, significantly more children in public schools were reported to still have asthma at the time of the survey (32.6% vs. 23.7%). Children attending public schools vs. private schools were reported to have missed significantly more school and to have had more hospitalizations and emergency department visits. Among children reported to still have asthma, significantly more children visited an emergency department, were hospitalized, and missed more school days due to respiratory symptoms in the past year. The high prevalence of parent-reported asthma, respiratory symptoms, and healthcare utilization among Puerto Rican children in San Juan calls for further studies using objective methods for ascertaining asthma and asthma-related morbidity. Differences in healthcare utilization between children attending public vs. private schools suggest that socioeconomic factors play a role in asthma management in Puerto Rico.

Substituted judgement: should life-support decisions be made by a surrogate?

OBJECTIVE: To evaluate the utility of the substituted judgement standard in terminally ill patients by determining agreement between patients, family proxies and physicians. BACKGROUND: Several studies have addressed the utility of substituted judgement, showing conflicting data whether surrogates are accurate predicting patient's wishes. METHODS: Patients with acquired immunodeficiency syndrome, congestive heart failure, chronic liver disease admitted to the San Juan Veterans Affairs Medical Center in Puerto Rico from November 1997 to February 1998 were evaluated. A questionnaire presented three hypothetical situations on withholding and withdrawal of life-support and CPR. The percent agreement was used as a measure of concordance between choices made by physician, surrogate and patients. RESULTS: Twenty patients met inclusion criteria (5 chronic liver disease, 9 heart failure, 6 AIDS). Relatives had a higher percent of agreement as compared to physicians in all vignettes. Even though, none did better than chance in predicting patient's wishes (k < 0.4). There was a tendency for relatives not to provide a wanted life-support measure, and for physicians to provide an unwanted life-support measure. CONCLUSION: The poor agreement between patients and surrogates suggests that substituted judgement is not an accurate tool to make end-of-life decisions. These findings, although similar to previous published studies, are unique because the direction of discrepant responses is opposite to the findings of studies published elsewhere. These results could reflect religious, cultural and socioeconomic differences.