Sleep disordered breathing and mortality: eighteen-year follow-up of the Wisconsin sleep cohort

BACKGROUND: Sleep-disordered breathing (SDB) is a treatable but markedly under-diagnosed condition of frequent breathing pauses during sleep. SDB is linked to incident cardiovascular disease, stroke, and other morbidity. However, the risk of mortality with untreated SDB, determined by polysomnography screening, in the general population has not been established. METHODS: An 18-year mortality follow-up was conducted on the population-based Wisconsin Sleep Cohort sample (n = 1522), assessed at baseline for SDB with polysomnography, the clinical diagnostic standard. SDB was described by the number of apnea and hypopnea episodes/hour of sleep; cutpoints at 5, 15 and 30 identified mild, moderate, and severe SDB, respectively. Cox proportional hazards regression was used to estimate all-cause and cardiovascular mortality risks, adjusted for potential confounding factors, associated with SDB severity levels. RESULTS: All-cause mortality risk, adjusted for age, sex, BMI, and other factors was significantly increased with SDB severity. The adjusted hazard ratio (HR, 95% CI) for all-cause mortality with severe versus no SDB was 3.0 (1.4,6.3). After excluding persons who had used CPAP treatment (n = 126), the adjusted HR (95% CI) for all-cause mortality with severe versus no SDB was 3.8 (1.6,9.0); the adjusted HR (95% CI) for cardiovascular mortality was 5.2 (1.4,19.2). Results were unchanged after accounting for daytime sleepiness. CONCLUSIONS: Our findings of a significant, high mortality risk with untreated SDB, independent of age, sex, and BMI underscore the need for heightened clinical recognition and treatment of SDB, indicated by frequent episodes of apnea and hypopnea, irrespective of symptoms of sleepiness.     

Unbiased categorical classification of pediatric sleep disordered breathing

Study Objectives:

To classify pediatric sleep disordered breathing (SDB) using unbiased approaches. In children, decisions regarding severity and treatment of SDB are conducted solely based on empirical observations. Although recognizable entities clearly exist under the SDB spectrum, neither the number of SDB categories nor their specific criteria have been critically defined.

Design:

retrospective cohort analysis and random prospective cohort

Setting:

community and clinical sample

Patients or Participants:

Urban 5- to 9-year-old community children undergoing overnight sleep study (NPSG), and a comparable prospectively recruited clinical SDB sample.

Interventions:

n/a

Measurements and Results:

Principal component analysis was used to identify the uniqueness of the polysomnographically derived measures that are routinely used in clinical settings: apnea-hypopnea index, apnea index, obstructive apnea index, nadir SpO₂, spontaneous arousal index and respiratory arousal index. These measures were then incorporated using unbiased data mining approaches to further characterize and discriminate across categorical phenotypes. Of 1,133 subjects, 52.8% were habitual snorers. Six categorical phenotypes clustered without any a priori hypothesis. Secondly, a non-hierarchical model that incorporated 6 NPSG-derived measures enabled unbiased identification of algorithms that predicted these 6 severity-based clusters. Thirdly, a hierarchical model was developed and performed well on all severity-based clusters. Classification and predictive models were subsequently cross-validated statistically as well as clinically, using 2 additional datasets that included 259 subjects. Modeling reached ∼93% accuracy in cluster assignment.

Conclusions:

Data-driven analysis of conventional NPSG-derived indices identified 6 distinct clusters ranging from a cluster with normal indices toward clusters with more abnormal indices. Categorical assignment of individual cases to any of such clusters can be accurately predicted using a simple algorithm. These clusters may further enable prospective unbiased characterization of clinical outcomes and of genotype-phenotype interactions across multiple datasets.

Citation:

Spruyt K; Verleye G; Gozal D. Unbiased categorical classification of pediatric sleep disordered breathing. SLEEP 2010;33(10):1341-1347.     

Sleep-disordered breathing and cardiovascular disease in the Bay Area Sleep Cohort

STUDY OBJECTIVES: To examine the relationship between sleep-disordered breathing (SDB) and cardiovascular disease among community-dwelling older adults. Previous studies have suggested relatively stronger associations between SDB and such morbidity in middle-aged, relative to elderly, populations. DESIGN: Cross-sectional analysis of an elderly ambulatory, non-clinic-based cohort (Bay Area Sleep Cohort, BASC) SETTING: Community population studied in a sleep laboratory PARTICIPANTS: One hundred twenty-nine older adults (mean [+/- SD] age = 72.6 [8.3]) (78 women; 51 men). INTERVENTIONS: NA. MEASUREMENTS: Complete clinical history including list of current medications, physical examination, selected blood chemistries, multiple blood pressure measurements, 12-lead electrocardiogram, and 2 consecutive nights of polysomnography. RESULTS: Fifty-one individuals (40%) were taking 1 or more cardiovascular medications and 24 (19%) had an apnea-hypopnea index (AHI) of 10 or more per hour of sleep. Cardiovascular medication use was related to cardiac events or procedures, history of angina, higher systolic or diastolic blood pressure, and abnormal electrocardiogram. Logistic regression showed statistically significant association between cardiovascular medication use and AHI of 10 or greater per hour, independent of age, sex, and body mass index. Supplementary analyses indicated that rapid eye movement AHI of 10 or greater per hour was significantly associated with elevated diastolic blood pressure. CONCLUSIONS: The results suggest that sleep-disordered breathing may contribute to increased cardiovascular morbidity in older adults.     

Sleep-disordered breathing in healthy and spousally bereaved elderly: A one-year follow-up study

This study examined the progression of sleep-disordered breathing (SDB) over 1 year in two samples of elderly subjects: 45 healthy controls (20 men; 25 women mean age 74.8 years) and 27 recently spousally bereaved elders (9 men; 18 women, mean age 69.7 years). Although controls and bereaved subjects did not differ in the proportions with SDB, both groups showed a rise in the proportion of subjects with apnea hypopnea index ≥ 5 and ≥ 10 at 1-year follow-up and a small but statistically significant worsening in average maximum desaturation. The severity of SDB did not correlate with medical burden or with other clinical variables, such as severity of depressive symptoms. In summary, SDB increased longitudinally in both samples. This finding may have health implications for the aging population although at this time the implications are unclear.     

Mandible behaviour interpretation during wakefulness,sleep and sleep‐disordered breathing

The mandible movement (MM) signal provides information on mandible activity. It can be read visually to assess sleep–wake state and respiratory events. This study aimed to assess (1) the training of independent scorers to recognize the signal specificities; (2) intrascorer reproducibility and (3) interscorer variability. MM was collected in the mid‐sagittal plane of the face of 40 patients. The typical MM was extracted and classified into seven distinct pattern classes: active wakefulness (AW), quiet wakefulness or quiet sleep (QW/S), sleep snoring (SS), sleep obstructive events (OAH), sleep mixed apnea (MA), respiratory related arousal (RERA) and sleep central events (CAH). Four scorers were trained; their diagnostic capacities were assessed on two reading sessions. The intra‐ and interscorer agreements were assessed using Cohen's κ. Intrascorer reproducibility for the two sessions ranged from 0.68 [95% confidence interval (CI): 0.59–0.77] to 0.88 (95% CI: 0.82–0.94), while the between‐scorer agreement amounted to 0.68 (95% CI: 0.65–0.71) and 0.74 (95% CI: 0.72–0.77), respectively. The overall accuracy of the scorers was 75.2% (range: 72.4–80.7%). CAH MMs were the most difficult to discern (overall accuracy 65.6%). For the two sessions, the recognition rate of abnormal respiratory events (OAH, CAH, MA and RERA) was excellent: the interscorer mean agreement was 90.7% (Cohen's κ: 0.83; 95% CI: 0.79–0.88). The discrimination of OAH, CAH, MA characteristics was good, with an interscorer agreement of 80.8% (Cohen's κ: 0.65; 95% CI: 0.62–0.68). Visual analysis of isolated MMs can successfully diagnose sleep–wake state, normal and abnormal respiration and recognize the presence of respiratory effort.     

Sleep-disordered breathing and oxidative stress in preclinical chronic mountain sickness (excessive erythrocytosis)

Chronic mountain sickness (CMS) is considered to be a loss of ventilatory acclimatization to high altitude (>2500 m) resulting in marked arterial hypoxemia and polycythemia. This case–control study explores the possibility that sleep-disordered breathing (SDB) and associated oxidative stress contribute to the etiology of CMS. Nocturnal respiratory and Sa_O2${\text{Sa}}_{{\text{O}}_2}$ patterns were measured using standard polysomnography techniques and compared between male high-altitude residents (aged 18–25) with preclinical CMS (excessive erythrocytosis (EE), n = 20) and controls (n = 19). Measures of oxidative stress and antioxidant status included isoprostanes (8-iso-PGF2_alpha), superoxide dismutase and ascorbic acid. EE cases had a greater apnea–hypopnea index, a higher frequency of apneas (central and obstructive) and hypopneas during REM sleep, and lower nocturnal Sa_O2${\text{Sa}}_{{\text{O}}_2}$ compared to controls. 8-iso-PGF2_alpha was greater in EE than controls, negatively associated with nocturnal Sa_O2${\text{Sa}}_{{\text{O}}_2}$, and positively associated with hemoglobin concentration. Mild sleep-disordered breathing and oxidative stress are evident in preclinical CMS, suggesting that the resolution of nocturnal hypoxemia or antioxidant treatment may prevent disease progression.     

Behavioral control of abnormal breathing in sleep

Behavioral control of abnormal breathing in sleep was studied to determine if an intervention procedure could reduce apnea duration and also SaO ₂ (blood oxygen) desaturation levels. Sleep apnea patients (n=11) were instructed while awake that tones would be presented in sleep whenever an apnea event occurred. They were told to breathe deeply to the tones and were given practice in doing so. Intervention and nonintervention hours alternated across 2 nights following 2 baseline nights. As expected, during the intervention hours, the duration but not the frequency of apneic events was reduced. The procedure also resulted in higher SaO ₂ levels during the intervention hours. Daytime sleepiness was not greater following intervention but sleep staging effects were observed. The results are sufficiently promising to warrant additional research.This research was supported by NIH Grants 2 HL 27149-84 and HL 34125 entitled Behavioral Control of Respiration in Sleep.     

Sleep‐disordered breathing in major depressive disorder

Individuals with major depressive disorder often experience obstructive sleep apnea. However, the relationship between depression and less severe sleep‐disordered breathing is unclear. This study examined the rate of sleep‐disordered breathing in depression after excluding those who had clinically significant sleep apnea (>5 apneas?h^?1). Archival data collected between 1991 and 2005 were used to assess the prevalence of sleep‐disordered breathing events in 60 (31 depressed; 29 healthy controls) unmedicated participants. Respiratory events were automatically detected using a program developed in‐house measuring thermal nasal air‐flow and chest pressure. Results show that even after excluding participants with clinically significant sleep‐disordered breathing, individuals with depression continue to exhibit higher rates of sleep‐disordered breathing compared with healthy controls (depressed group: apnea–hypopnea index mean = 0.524, SE = 0.105; healthy group: apnea–hypopnea index mean = 0.179, SE = 0.108). Exploratory analyses were also conducted to assess for rates of exclusion in depression studies due to sleep‐disordered breathing. Study exclusion of sleep‐disordered breathing was quantified based on self‐report during telephone screening, and via first night polysomnography. Results from phone screening data reveal that individuals reporting depression were 5.86 times more likely to report a diagnosis of obstructive sleep apnea than presumptive control participants. Furthermore, all of the participants excluded for severe sleep‐disordered breathing detected on the first night were participants with depression. These findings illustrate the importance of understanding the relationship between sleep‐disordered breathing and depression, and suggest that screening and quantification of sleep‐disordered breathing should be considered in depression research.     

Sleep disordered breathing in pregnancy: A review of the pathophysiology of adverse pregnancy outcomes

Sleep disordered breathing (SDB) is a common obesity‐related co‐morbidity with strong associations to cardiometabolic disease. The risk of SDB is increased during pregnancy, particularly among obese pregnant women. Accumulating evidence suggests that an association exists between maternal SDB and the development of adverse pregnancy outcomes, particularly gestational diabetes and hypertensive disorders of pregnancy. Intermittent hypoxia, a central characteristic of SDB, has been shown in animal and clinical studies to dysregulate several biological pathways. This includes the promotion of oxidative stress, increased inflammation, activation of the hypothalamic‐pituitary‐adrenal axis, increased sympathetic activity and impaired glucose and insulin metabolism. This review considers how, during pregnancy, these pathophysiological processes are plausible mechanisms through which SDB may contribute to an increased risk of adverse outcomes, for the mother and perhaps also the offspring. However, a lack of robust evidence specific to the pregnant population, including limited evaluation of the placental function in affected pregnancies, limits our ability to draw definite conclusions on mechanisms contributing to adverse pregnancy outcomes and, indeed, the strength of association between SDB and certain pregnancy complications.     

Behavior problems associated with sleep disordered breathing in school-aged children--the Tucson children's assessment of sleep apnea study

OBJECTIVE: The purpose of the current study was to examine prevalence of and relations between a commonly used measure of nighttime breathing problems, the Respiratory Disturbance Index (RDI), and a range of problem behaviors in community children. METHODS: Participants were 403 unreferred children aged 6-12 years. Recruitment was completed through public elementary schools. Overnight unattended in-home polysomnography was used to assess sleep and breathing. The RDI was used as the indicator of respiratory events during sleep. The Child Behavior Checklist and the Conners' Parent Rating Scales-Revised were used to assess behavior. RESULTS: Prevalence rates for Attention, Cognitive Problems, Aggression, Oppositional behavior, and Social Problems were greatest for subjects with high RDIs. Prevalence for Internalizing behaviors was not greater for those subjects with high RDIs. Hyperactivity was not strongly related to higher RDIs. CONCLUSIONS: Behavioral problems may exist in the presence of nocturnal breathing events in unreferred children. Specific patterns of behavioral morbidity have still not been established. Some behaviors, such as hyperactivity, may show differing sensitivity and specificity in relation to the RDI.     

Respiratory polygraphy in children with sleep‐disordered breathing

At‐home respiratory polygraphy has been shown to be a reliable substitute for in‐laboratory polysomnography in adults for diagnosing obstructive sleep apnea, but this is less well studied in children. One aim of this study was to examine the quality of at‐home respiratory polygraphy in children with sleep‐disordered breathing and to evaluate the interrater reliability of the results. Another aim was to study whether calibrated respiratory inductance plethysmography (RIP) flow can be used for the scoring of respiratory events when the airflow measurements are unreliable. Children aged 4–10 years, with sleep‐disordered breathing, underwent at‐home respiratory polygraphy. Of 113 polygraphies, only 46% were of acceptable quality, with missing nasal airflow being the most common problem (40%). The median recorded time with artifact‐free signal present in three traces simultaneously was 228 min (0–610 min). Seventeen polygraphy studies were selected for further study. Each study was scored by two independent scorers, with and without the nasal airflow signal present, the latter relying on RIP flow for the scoring of respiratory events. The apnea–hypopnea index (AHI) from the four different measurements was compared using intraclass correlation coefficients (ICC). Comparison of the two scorers showed moderate agreement, with (ICC = 0.66) and without (ICC = 0.53) nasal airflow. One scorer had good agreement between AHI with and without nasal airflow (ICC = 0.81), whereas the other had poor agreement (ICC = 0.12). In conclusion, the scoring of respiratory events based on RIP flow is scorer dependent even for experienced scorers. The nasal airflow signal is frequently missing in paediatric respiratory polygraphies, which limits the usefulness of the method.     

Sleep‐disordered breathing in children with mucolipidosis

Mucolipidosis (ML) is a rare lysosomal storage disorder with a wide spectrum of disease severity according to the type. Sleep‐disordered breathing is recognized as a characteristic feature of ML but objective data are scarce. The aim of the study was to describe sleep data and medical management in children with ML α/β. All patients with ML α/β followed at a national reference center of ML were included. Five patients had ML II, one patient had ML III and one patient had ML II‐III. One patient was started on noninvasive ventilation (NIV) to allow extubation after prolonged invasive mechanical ventilation. The six other patients underwent sleep study at a median age of 1.8 years (range 4 months–17.4 years). Obstructive sleep apnea (OSA) was observed in all patients with a median apnea‐hypopnea index (AHI) of 36 events/hr (range 5–52) requiring continuous positive airway pressure (CPAP) or NIV. CPAP/NIV resulted in an improvement of nocturnal gas exchange and was continued in all patients with an excellent compliance. Two patients died. Systematic sleep studies are recommended at time of diagnosis in ML. CPAP or NIV are effective treatments of OSA, well tolerated, and may contribute to improve the quality of life of patients and caregivers.     

Premature infants in car seats: effect of sleep state on breathing

SUMMARY  Previous studies have shown that premature infants may be at risk for hypoxemia and bradycardia when placed in standard car seats. However, the relationship of such breathing abnormalities to sleep state have not been studied. The purpose of the present study was to investigate the effect of car seat positioning on respiratory patterns in preterm infants during sleep and to evaluate their relationship to sleep state. Complete polysomnography, including sleep and breathing parameters, was performed on twenty-eight premature infants. Each infant was randomly assigned to the car seat or prone (crib) position for the first recording period. Following the recording of at least two sleep cycles, the position was reversed. The percentage of active and quiet sleep was calculated and breathing parameters were measured. In the car seat, the infants spent significantly more time in active sleep and less time in quiet sleep than in the prone position, of the respiratory parameters, periodic breathing (PB) was significantly higher in the car seat. The presence of at least one abnormal breathing events (bradycardia, desaturation, PB apnoea) was also significantly higher in the car seat. An analysis of variance (ANOVA) of PB revealed significant sleep-state effect (active vs. quiet sleep), but no significant condition or interaction effects, indicating that PB was more frequent in active sleep regardless of the sleeping condition. It is concluded that increased active sleep in the car seat condition, rather than the positioning of the infant in the seat per se, may account for the increase in periodic breathing and possibly other breathing abnormalities reported in car seats.     

空腹血糖正常的冠心病患者糖代谢状况及胰岛素水平分析

目的：探讨空腹血糖正常的冠心病患者的糖代澍状况及胰岛素敏感性的改变。方法：检测67例空腹血糖正常的冠心病住院患者和35例健康者的空腹及餐后2h的血糖和胰岛索水平,并根据餐后2h血糖结果将冠心病患者分为3组：正常糖耐量组（NGT）、单纯性糖耐量受损组（I—IGT）、单纯性负荷后高血精组（IPH）。应用李光伟指数（IAI）评价机体的胰岛素敏感性。结果：67例空腹血糖正常的冠心病患者中糖代谢异常的发生率为74．63％,所有冠心病患音餐后胰岛素水平显著高于正常对照组（P〈0．05）,IPH组的胰岛素敏感性显著低于其他各组（P均〈0．05）。结论：空腹血糖正常的冠心病患者中绝大多数合并糖代谢异常,并存在高胰岛索血症,合并IPH的冠心病患者胰岛素的敏感性较低。检测餐后血糖和胰岛素对冠心病患者合并糖代谢异常的预防、诊断、疗效评估有重要意义。     

Sleep‐disordered breathing in children with pycnodysostosis

Upper airway obstruction is a common feature in pycnodysostosis and may cause obstructive sleep apnea (OSA). The aim of our study was to analyze sleep‐disordered breathing and respiratory management in children with pycnodysostosis. A retrospective review of the clinical charts and sleep studies of 10 consecutive children (three girls and seven boys) with pycnodysostosis seen over a time period of 10 years was performed. Six patients had severe OSA and/or nocturnal hypoventilation and were started on continuous positive airway pressure (CPAP) as a first treatment at a median age of 3.4 ± 2.6 years, because of the lack of indication of any surgical treatment. Three patients could be weaned after several years from CPAP after spontaneous improvement (two patients) or multiple upper airway surgeries (one patient). Three patients had upper airway surgery prior to their first sleep study with two patients still needing CPAP during their follow‐up. Only one patient never developed OSA. Patients with pycnodysostosis are at a high risk of severe OSA, underlying the importance of a systematic screening for sleep‐disordered breathing. Multidisciplinary care is mandatory because of the multilevel airway obstruction. CPAP is very effective and well accepted for treating OSA.     

Effect of expiratory positive airway pressure on sleep disordered breathing

STUDY OBJECTIVES: We sought to determine the effect of expiratory positive airway pressure on end expiratory lung volume (EELV) and sleep disordered breathing in obstructive sleep apnea patients. DESIGN: Observational physiology study PARTICIPANTS: We studied 10 OSA patients during sleep wearing a facial mask. We recorded 1 hour of NREM sleep without treatment (baseline) and 1 hour with 10 cm H2O EPAP in random order, while measuring EELV and breathing pattern. RESULTS: The mean EELV change between baseline and EPAP was only 13.3 mL (range 2-25 mL). Expiratory time was significantly increased with EPAP compared to baseline 2.64 +/- 0.54 vs 2.16 +/- 0.64 sec (P = 0.002). Total respiratory time was longer with EPAP than at baseline 4.44 +/- 1.47 sec vs 3.73 +/- 0.88 sec (P = 0.3), and minute ventilation was lower with EPAP vs baseline 7.9 +/- 4.17 L/min vs 9.05 +/- 2.85 L/min (P = 0.3). For baseline (no treatment) and EPAP respectively, the mean apnea+hypopnea index (AHI) was 62.6 +/- 28.7 and 56.8 +/- 30.3 events per hour (P = 0.4). CONCLUSION: In OSA patients during sleep, the application of 10 cm H2O EPAP led to prolongation of expiratory time with only marginal increases in FRC. These findings suggest important mechanisms exist to avoid hyperinflation during sleep.     

Sleep disordered breathing (SDB) experiences associated with snoring in adult Nigerians

Background

Snorers often experience symptoms of sleep disordered breathing (SDB) which is largely undiagnosed in the population. Information on SDB experiences is needed to target high-risk individuals that may benefit from treatment of snoring.

Objective

This study compares the experience of the nighttime and daytime symptoms of SDB of habitual snorers with that of non-habitually snoring adult subjects in a tertiary health facility in Nigeria.

Methods

A cross-sectional, comparative, hospital based study was conducted. Berlin questionnaire was administered to consecutive adult patients (subjects) attending ENT Clinic of OOUTH, Sagamu, Nigeria. Based on the responses to their experience of snoring, the subjects were categorized as habitual snorers or non-habitual snorers. General physical examinations with emphases on the nose, throat and neck were performed on the subjects. The experiences of nighttime and daytime symptoms of SDB were recorded and those of habitual snorers compared to non-habitual snorers.

Results

One hundred and ninety- five subjects participated in the study. M:F =1.3:1. Overall prevalence of snoring was 37.9% and habitual snoring was 18.5%. Habitual snoring was significantly associated with age, marital status and obesity (BMI>=30.0). There were statistically significant increased odds of experiencing the nighttime and daytime symptoms of SDB in habitual snorers compared to non-habitual snorers.

Conclusion

Adults that snore habitually had significantly more nighttime and daytime symptoms of SDB compared to those who do not snore habitually. Habitual snoring predisposes adult subjects to experiencing symptoms of SDB.     

Impact of sleep‐disordered breathing in patients with acute myocardial infarction: a retrospective analysis

Sleep‐disordered breathing (SDB) is associated with an increased risk of cardiovascular events. Previous studies showed that severe SDB has a negative impact on myocardial salvage and progression of left ventricular dysfunction after acute myocardial infarction (AMI). This study investigated the frequency of SDB and the effects of SDB on left ventricular function after AMI. This retrospective study enrolled all patients with AMI who had undergone cardiorespiratory polygraphy for SDB diagnosis. The apnea–hypopnea index was used as a standard metric of SDB severity. SDB was classified as mild (apnea–hypopnea index >5 to <15 per h), moderate (≥15 to <30 per h) or severe (apnea–hypopnea index ≥30 per h). According to the majority of events, SDB was classified as predominant obstructive sleep apnea, central sleep apnea or mixed sleep apnea (mixed SDB). A total of 223 patients with AMI (112 with ST elevation and 111 without ST elevation; 63.2 ± 11.2 years, 82% male, left ventricular ejection fraction 49 ± 12%) were enrolled. SDB was present in 85.6%, and was moderate‐to‐severe in 63.2%; 40.8% had obstructive sleep apnea, 41.7% had central sleep apnea and 3.1% had mixed SDB. Left ventricular ejection fraction was lower in patients with AMI with severe SDB (45 ± 14%) versus those without SDB (57 ± 7%; P < 0.005). In addition, lower left ventricular ejection fraction (≤45%) was associated with increased frequency (apnea–hypopnea index ≥5 per h in 96%) and severity (apnea–hypopnea index ≥30 per h in 48%) of SDB in general and a higher percentage of central sleep apnea (57%) in particular. SDB is highly frequent in patients with AMI. SDB severity appeared to be linked to impaired left ventricular function, especially in patients with central sleep apnea.     

The effect of lowering the threshold for diagnosis of impaired fasting glucose

PURPOSE: The aim of this study was to evaluate the effect of lowering the fasting plasma glucose (FPG) criteria for impaired fasting glucose (IFG) on the prevalence of IFG and the risk for the development of diabetes associated with IFG in Koreans. MATERIALS AND METHODS: A total of 7,211 subjects who had normal glucose tolerance (NGT) or IFG were recruited. Subjects were evaluated at baseline and after two years follow up. Clinical data including total cholesterol, FPG and blood pressure were examined. RESULTS: Lowering the criteria for IFG from 6.1 mmol/L (110 mg/dL) to 5.6 mmol/L (100 mg/dL) increased the prevalence of IFG from 6.6% (494 subjects) to 24.4% (1829 subjects). After the 2 years follow up period, 91 subjects (1.3%) developed diabetes. Twenty one (0.3%) subjects developed diabetes among 5,382 NGT subjects and 70 (3.8%) subjects developed diabetes among 1,829 IFG (5.6-7.0 mmol/L) subjects. Lowering the IFG threshold from 6.1 mmol/L to 5.6 mmol/L resulted in a 18.4% decrease in specificity and 23.9% increase in sensitivity for predicting diabetes. The baseline FPG for predicting the development of diabetes after 2 years at a point on the receiver operating characteristic curve that was closest to the ideal 100% sensitivity and 100% specificity was 5.7 mmol/L (103 mg/dL). CONCLUSION: Lowering the FPG criterion of IFG should have benefits in predicting new onset type 2 diabetes mellitus in Koreans. The economic and health benefits of applying the new IFG criteria should be evaluated in future studies.