Exploratory study of ultraviolet B (UVB) radiation and age of onset of bipolar disorder

BACKGROUND

Sunlight contains ultraviolet B (UVB) radiation that triggers the production of vitamin D by skin. Vitamin D has widespread effects on brain function in both developing and adult brains. However, many people live at latitudes (about > 40 N or S) that do not receive enough UVB in winter to produce vitamin D. This exploratory study investigated the association between the age of onset of bipolar I disorder and the threshold for UVB sufficient for vitamin D production in a large global sample.

METHODS

Data for 6972 patients with bipolar I disorder were obtained at 75 collection sites in 41 countries in both hemispheres. The best model to assess the relation between the threshold for UVB sufficient for vitamin D production and age of onset included 1 or more months below the threshold, family history of mood disorders, and birth cohort. All coefficients estimated at P ≤ 0.001.

RESULTS

The 6972 patients had an onset in 582 locations in 70 countries, with a mean age of onset of 25.6 years. Of the onset locations, 34.0% had at least 1 month below the threshold for UVB sufficient for vitamin D production. The age of onset at locations with 1 or more months of less than or equal to the threshold for UVB was 1.66 years younger.

CONCLUSION

UVB and vitamin D may have an important influence on the development of bipolar disorder. Study limitations included a lack of data on patient vitamin D levels, lifestyles, or supplement use. More study of the impacts of UVB and vitamin D in bipolar disorder is needed to evaluate this supposition.

Association between polarity of first episode and solar insolation in bipolar I disorder

OBJECTIVE

Circadian rhythm disruption is commonly observed in bipolar disorder (BD). Daylight is the most powerful signal to entrain the human circadian clock system. This exploratory study investigated if solar insolation at the onset location was associated with the polarity of the first episode of BD I. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area of the Earth.

METHODS

Data from 7488 patients with BD I were collected at 75 sites in 42 countries. The first episode occurred at 591 onset locations in 67 countries at a wide range of latitudes in both hemispheres. Solar insolation values were obtained for every onset location, and the ratio of the minimum mean monthly insolation to the maximum mean monthly insolation was calculated. This ratio is largest near the equator (with little change in solar insolation over the year), and smallest near the poles (where winter insolation is very small compared to summer insolation). This ratio also applies to tropical locations which may have a cloudy wet and clear dry season, rather than winter and summer.

RESULTS

The larger the change in solar insolation throughout the year (smaller the ratio between the minimum monthly and maximum monthly values), the greater the likelihood the first episode polarity was depression. Other associated variables were being female and increasing percentage of gross domestic product spent on country health expenditures. (All coefficients: P ≤ 0.001).

CONCLUSION

Increased awareness and research into circadian dysfunction throughout the course of BD is warranted.

Variations in seasonal solar insolation are associated with a history of suicide attempts in bipolar I disorder

Background

Bipolar disorder is associated with circadian disruption and a high risk of suicidal behavior. In a previous exploratory study of patients with bipolar I disorder, we found that a history of suicide attempts was associated with differences between winter and summer levels of solar insolation. The purpose of this study was to confirm this finding using international data from 42% more collection sites and 25% more countries.

Methods

Data analyzed were from 71 prior and new collection sites in 40 countries at a wide range of latitudes. The analysis included 4876 patients with bipolar I disorder, 45% more data than previously analyzed. Of the patients, 1496 (30.7%) had a history of suicide attempt. Solar insolation data, the amount of the sun’s electromagnetic energy striking the surface of the earth, was obtained for each onset location (479 locations in 64 countries).

Results

This analysis confirmed the results of the exploratory study with the same best model and slightly better statistical significance. There was a significant inverse association between a history of suicide attempts and the ratio of mean winter insolation to mean summer insolation (mean winter insolation/mean summer insolation). This ratio is largest near the equator which has little change in solar insolation over the year, and smallest near the poles where the winter insolation is very small compared to the summer insolation. Other variables in the model associated with an increased risk of suicide attempts were a history of alcohol or substance abuse, female gender, and younger birth cohort. The winter/summer insolation ratio was also replaced with the ratio of minimum mean monthly insolation to the maximum mean monthly insolation to accommodate insolation patterns in the tropics, and nearly identical results were found. All estimated coefficients were significant at p < 0.01.

Conclusion

A large change in solar insolation, both between winter and summer and between the minimum and maximum monthly values, may increase the risk of suicide attempts in bipolar I disorder. With frequent circadian rhythm dysfunction and suicidal behavior in bipolar disorder, greater understanding of the optimal roles of daylight and electric lighting in circadian entrainment is needed.

Promising Applications of Additive-Manufactured (3D-printed) Electrochemical Sensors for Forensic Chemistry

Additive-manufacturing is one of the major pillars of the new industrial revolution and the three-dimensional (3D) printing technology has been highlighted in this scenario. Among the many areas benefited by 3D-printing, the development of electrochemical sensors has appeared in evidence in the last years. One potential application of 3D-printed electrochemical sensors is devoted to forensic chemistry, which demands for portable analytical methods that can provide on-site measurements and thus bring a relevant information in loco. In this context, this review highlights the recent contribution of 3D-printing technology on the development of electrochemical sensors with great promises for on-site analysis in “real-world” forensic scenarios. From the detection of trace explosives, gunshot residues, illicit drugs and chemical threats, to the measurement of adulterants in food and fuels, we show the wide range of applications that 3D-printed electrochemical sensors have been proposed and future demands that can be addressed by such a powerful, affordable, and accessible tool.

Do antidepressants influence mood patterns? A naturalistic study in bipolar disorder

This prospective, longitudinal study compared the frequency and pattern of mood changes between outpatients receiving usual care for bipolar disorder who were either taking or not taking antidepressants. One hundred and eighty-two patients with bipolar disorder self-reported mood and psychiatric medications for 4 months using a computerized system (ChronoRecord) and returned 22,626 days of data. One hundred and four patients took antidepressants, 78 did not. Of the antidepressants taken, 95% were selective serotonin or norepinephrine reuptake inhibitors, or second-generation antidepressants. Of the patients taking an antidepressant, 91.3% were concurrently taking a mood stabilizer. The use of antidepressants did not influence the daily rate of switching from depression to mania or the rate of rapid cycling, independent of diagnosis of bipolar I or II. The primary difference in mood pattern was the time spent normal or depressed. Patients taking antidepressants frequently remained in a subsyndromal depression. In this naturalistic study using self-reported data, patients with bipolar disorder who were taking antidepressants—overwhelmingly not tricyclics and with a concurrent mood stabilizer—did not experience an increase in the rate of switches to mania or rapid cycling compared to those not taking antidepressants. Antidepressants had little impact on the mood patterns of bipolar patients taking mood stabilizers.

Influence of birth cohort on age of onset cluster analysis in bipolar I disorder

Purpose:

Two common approaches to identify subgroups of patients with bipolar disorder are clustering methodology (mixture analysis) based on the age of onset, and a birth cohort analysis. This study investigates if a birth cohort effect will influence the results of clustering on the age of onset, using a large, international database.

Methods:

The database includes 4037 patients with a diagnosis of bipolar I disorder, previously collected at 36 collection sites in 23 countries. Generalized estimating equations (GEE) were used to adjust the data for country median age, and in some models, birth cohort. Model-based clustering (mixture analysis) was then performed on the age of onset data using the residuals. Clinical variables in subgroups were compared.

Results:

There was a strong birth cohort effect. Without adjusting for the birth cohort, three subgroups were found by clustering. After adjusting for the birth cohort or when considering only those born after 1959, two subgroups were found. With results of either two or three subgroups, the youngest subgroup was more likely to have a family history of mood disorders and a first episode with depressed polarity. However, without adjusting for birth cohort (three subgroups), family history and polarity of the first episode could not be distinguished between the middle and oldest subgroups.

Conclusion:

These results using international data confirm prior findings using single country data, that there are subgroups of bipolar I disorder based on the age of onset, and that there is a birth cohort effect. Including the birth cohort adjustment altered the number and characteristics of subgroups detected when clustering by age of onset. Further investigation is needed to determine if combining both approaches will identify subgroups that are more useful for research.

P4344An example that big data analysis is ready for the prime time

Introduction

Data about the epidemiology of valvular heart disease (VHD) is scarce. The increasing aging of the population may cause an augmented prevalence of VHD, with a great number of comorbidities that conveys a higher surgical risk. The aim of this study was to describe the prevalence of VHD in the patients attended at our institution from 2007 until 2017 and to describe the main characteristics of this population.

Methods

We used a new tool based on EHRead Technology to extract clinical relevant information from Electronic Health Records, designed for descriptive and predictive big data analysis. All medical reports generated at the outpatient clinic, ER or hospitalization ward were examined. Patients with a diagnosis of moderate or severe VHD were selected. The prevalence of VHD was also estimated in 2 quintiles, from 2008 until Feb 2013 and from March 2013 until Dec 2017.

Results

The total prevalence of VHD in our population was 1.04% (n=3431). Mitral regurgitation was the most frequent valvular lesion (0.4%, n=1318), followed by aortic stenosis (0.3%, n=967) and aortic regurgitation (0.28%, n=938). There was a clear female predominance (63%), and the median age was 76.4. In the 1st quintile the prevalence of VHD was 0.25%, and increased to 0.79% in the 2nd. This trend was consistent in all type of valvular lesions. The prevalence of comorbidities was higher than in other epidemiological studies (Table).

Prevalence of comorbidities Severe MR Severe AS Severe AR Euro Heart Valve Survey Hypertension 54,5% 69,1% 47,9% 49% Dyslipidemia 32,2% 40,6% 27,4% 35% Diabetes Mellitus 28,0% 31,5% 16,4% 15% Smoking (current) 5,6% 5,4% 13,7% 39% Coronary heart disease 12,0% 17,0% 12,3% 13% Stroke 7,0% 8,9% 5,5% 7% Chronic kidney disease 18,9% 16,9% 20,5% 15% Chronic obstructive pulmonary disease 11,2% 9,9% 11,0% 15% MR: Mitral regurgitation, AS: aortic stenosis, AR: aortic regurgitation, MS: mitral stenosis.

Sex Distribution

Conclusions

The older age and greater number of comorbidities seen in our series over the past ten years, compared to the Euroheart Valve Survey reinforce the idea that the percutaneous valvular therapies should play a major role in the treatment of patients with VHD. Although, the prevalence of VHD may be underestimated in our population, due to the methodology, it reflects an ever-growing pathology in an older and sicker population.

P2750Why should cardiopulmonary exercise testing be routinely used for assessing patients with valvular heart disease?

Introduction

The role of cardiopulmonary exercise testing (CPET) is unquestionable to assess prognosis in heart failure. In patients with valvular heart disease (VHD), the functional capacity (FC) is crucial to aid in the right timing of surgery. The aim of this study was to compare the assessment of the FC by CPET and NYHA and the correlation between ventilatory efficiency parameters and resting systolic pulmonary artery pressure (SPAP).

Methods

We studied 100 VHD patients (57% female) who underwent a CPET. We calculated the real METS (RM) as indexed peak VO2/3.5 (1 MET=3.5 ml O2/kg/min) and compared to estimated METS (EM) derived by the time of exercise. An agreement analysis between RM, EM and NYHA was calculated. The correlation among VE/Vslope CO2, EqCO2at anaerobic threshold (AT), PETCO2, partial pressure end-tidal CO2 at AT and SPAP was analyzed.

Results

The results are shown in Table and Figure. The RM and the EM were 4.7±1.7 and 5.5±3, respectively (p<0.01) with a low agreement (ICC=0.6, p<0.01). The agreement between NYHA and the classification obtained from peak % of predicted peak VO2 was very low (weighted kappa =0.06, p=0.28). In patients with severe mitral VHD, the ventilatory efficiency parameters were correlated with SPAP (PETCO2 (AT), r=−0.7, p=0.002; EqCO2 (AT), r=0.5, p=0.04:VE/Vslope CO2, r=0.3, p 0.2), whereas in those with severe aortic VHD, these correlations were much lower (PETCO2 (AT), r=−0.3, p=0.13; EqCO2 (AT), r=0.2, p=0.15; VE/Vslope CO2, r=0.18, p 0.31).

Total (n=100) Mitral regurgitation (n=35) Aortic regurgitation (n=23) Age 65 (29–86) 66 (30–84) 65 (11–87) LVEF (%) 62±6 63±6 61±7 SPAP (mmHg) 40±11 39±11 36±8 NYHA I (60%), II (33%), III (7%) I (63%), II (29%), III (9%) I (63%), II (33%), III (4%) Indexed peak VO2 (ml/min/kg) 16±6 17±6 19±8 Peak % predicted VO2 73±18 74±17 79±18 Predicted VO2 AT (%) 58±19 54±19 61±22 Eq CO2 AT 33±6 32±7 32±5 VE/VSlope CO2 33±6 32±7 33±8 PetCO2 AT 34±4 36±4 36±5

Type and degree of VHD

Conclusions

NYHA scale and estimation of METS derived from the time of exercise clearly overestimated the FC of our population. In our series, the ventilatory inefficiency in patients with mitral VHD could be a surrogate marker of advanced disease and could lead to an earlier intervention.

Trajectories of adherence to mood stabilizers in patients with bipolar disorder

Background

Nonadherence with mood stabilizers is a major problem that negatively impacts the course of bipolar disorder. Medication adherence is a complex individual behavior, and adherence rates often change over time. This study asked if distinct classes of adherence trajectories with mood stabilizers over time could be found, and if so, which patient characteristics were associated with the classes.

Methods

This analysis was based on 12 weeks of daily self-reported data from 273 patients with bipolar 1 or II disorder using ChronoRecord computer software. All patients were taking at least one mood stabilizer. The latent class mixed model was used to detect trajectories of adherence based on 12 weekly calculated adherence datapoints per patient.

Results

Two distinct trajectory classes were found: an adherent class (210 patients; 77%) and a less adherent class (63 patients; 23%). The characteristics associated with the less adherent class were: more time not euthymic (p < 0.001) and female gender (p = 0.016). No other demographic associations were found.

Conclusion

In a sample of motivated patients who complete daily mood charting, about one quarter were in the less adherent class. Even patients who actively participate in their care, such as by daily mood charting, may be nonadherent. Demographic characteristics may not be useful in assessing individual adherence. Future research on longitudinal adherence patterns in bipolar disorder is needed.

Association between solar insolation and a history of suicide attempts in bipolar I disorder

In many international studies, rates of completed suicide and suicide attempts have a seasonal pattern that peaks in spring or summer. This exploratory study investigated the association between solar insolation and a history of suicide attempt in patients with bipolar I disorder. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area on Earth. Data were collected previously from 5536 patients with bipolar I disorder at 50 collection sites in 32 countries at a wide range of latitudes in both hemispheres. Suicide related data were available for 3365 patients from 310 onset locations in 51 countries. 1047 (31.1%) had a history of suicide attempt. There was a significant inverse association between a history of suicide attempt and the ratio of mean winter solar insolation/mean summer solar insolation. This ratio is smallest near the poles where the winter insolation is very small compared to the summer insolation. This ratio is largest near the equator where there is relatively little variation in the insolation over the year. Other variables in the model that were positively associated with suicide attempt were being female, a history of alcohol or substance abuse, and being in a younger birth cohort. Living in a country with a state-sponsored religion decreased the association. (All estimated coefficients p < 0.01). In summary, living in locations with large changes in solar insolation between winter and summer may be associated with increased suicide attempts in patients with bipolar disorder. Further investigation of the impacts of solar insolation on the course of bipolar disorder is needed.

Intestine-Specific Overexpression of LDLR Enhances Cholesterol Excretion and Induces Metabolic Changes in Male Mice

Roux-en-Y gastric bypass (RYGB) surgery is one of the most effective treatment options for severe obesity and related comorbidities, including hyperlipidemia, a well-established risk factor of cardiovascular diseases. Elucidating the molecular mechanisms underlying the beneficial effects of RYGB may facilitate development of equally effective, but less invasive, treatments. Recent studies have revealed that RYGB increases low-density lipoprotein receptor (LDLR) expression in the intestine of rodents. Therefore, in this study we first examined the effects of RYGB on intestinal cholesterol metabolism in human patients, and we show that they also exhibit profound changes and increased LDLR expression. We then hypothesized that the upregulation of intestinal LDLR may be sufficient to decrease circulating cholesterol levels. To this end, we generated and studied mice that overexpress human LDLR specifically in the intestine. This perturbation significantly affected intestinal metabolism, augmented fecal cholesterol excretion, and induced a reciprocal suppression of the machinery related to luminal cholesterol absorption and bile acid synthesis. Circulating cholesterol levels were significantly decreased and, remarkably, several other metabolic effects were similar to those observed in RYGB-treated rodents and patients, including improved glucose metabolism. These data highlight the importance of intestinal cholesterol metabolism for the beneficial metabolic effects of RYGB and for the treatment of hyperlipidemia.

Internet use by older adults with bipolar disorder: international survey results

Background

The world population is aging and the number of older adults with bipolar disorder is increasing. Digital technologies are viewed as a framework to improve care of older adults with bipolar disorder. This analysis quantifies Internet use by older adults with bipolar disorder as part of a larger survey project about information seeking.

Methods

A paper-based survey about information seeking by patients with bipolar disorder was developed and translated into 12 languages. The survey was anonymous and completed between March 2014 and January 2016 by 1222 patients in 17 countries. All patients were diagnosed by a psychiatrist. General estimating equations were used to account for correlated data.

Results

Overall, 47% of older adults (age 60 years or older) used the Internet versus 87% of younger adults (less than 60 years). More education and having symptoms that interfered with regular activities increased the odds of using the Internet, while being age 60 years or older decreased the odds. Data from 187 older adults and 1021 younger adults were included in the analysis excluding missing values.

Conclusions

Older adults with bipolar disorder use the Internet much less frequently than younger adults. Many older adults do not use the Internet, and technology tools are suitable for some but not all older adults. As more health services are only available online, and more digital tools are developed, there is concern about growing health disparities based on age. Mental health experts should participate in determining the appropriate role for digital tools for older adults with bipolar disorder.

Time-Dependent Molecular Responses Differ between Gastric Bypass and Dieting but Are Conserved Across Species

The effectiveness of Roux-en-Y gastric bypass (RYGB) against obesity and its comorbidities has generated excitement about developing new, less invasive treatments that use the same molecular mechanisms. Although controversial, RYGB-induced improvement of metabolic function may not depend entirely upon weight loss. To elucidate the differences between RYGB and dieting, we studied several individual organ molecular responses and generated an integrative, interorgan view of organismal physiology. We also compared murine and human molecular signatures. We show that, although dieting and RYGB can bring about the same degree of weight loss, post-RYGB physiology is very different. RYGB induces distinct, organ-specific adaptations in a temporal pattern that is characterized by energetically demanding processes, which may be coordinated by HIF1a activation and the systemic repression of growth hormone receptor signaling. Many of these responses are conserved in rodents and humans and may contribute to the remarkable ability of surgery to induce and sustain metabolic improvement.

Regularity of self-reported daily dosage of mood stabilizers and antipsychotics in patients with bipolar disorder

BACKGROUND

Polypharmacy is often prescribed for bipolar disorder, yet medication non-adherence remains a serious problem. This study investigated the regularity in the daily dosage taken of mood stabilizers and second generation antipsychotics.

METHODS

Daily self-reported data on medications taken and mood were available from 241 patients with a diagnosis of bipolar disorder who received treatment as usual. Patients who took the same mood stabilizer or second generation antipsychotic for ≥ 100 days were included. Approximate entropy was used to determine serial regularity in daily dosage taken. Generalized estimating equations were used to estimate if demographic or clinical variables were associated with regularity.

RESULTS

There were 422 analysis periods available from the 241 patients. Patients took drugs on 84.4% of days. Considerable irregularity was found, mostly due to single-day omissions and dosage changes. Drug holidays (missing 3 or more consecutive days) were found in 35.8% of the analysis periods. Irregularity was associated with an increasing total number of psychotropic drugs taken (p = 0.009), the pill burden (p = 0.026), and the percent of days depressed (p = 0.049).

CONCLUSION

Despite low missing percent of days, daily drug dosage may be irregular primarily due to single day omissions and dosage changes. Drug holidays are common. Physicians should expect to see partial adherence in clinical practice, especially with complex drug regimens. Daily dosage irregularity may impact the continuity of drug action, contribute to individual variation in treatment response, and needs further study.

Solar insolation in springtime influences age of onset of bipolar I disorder

OBJECTIVE

To confirm prior findings that the larger the maximum monthly increase in solar insolation in springtime, the younger the age of onset of bipolar disorder.

METHOD

Data were collected from 5536 patients at 50 sites in 32 countries on six continents. Onset occurred at 456 locations in 57 countries. Variables included solar insolation, birth-cohort, family history, polarity of first episode and country physician density.

RESULTS

There was a significant, inverse association between the maximum monthly increase in solar insolation at the onset location, and the age of onset. This effect was reduced in those without a family history of mood disorders and with a first episode of mania rather than depression. The maximum monthly increase occurred in springtime. The youngest birth-cohort had the youngest age of onset. All prior relationships were confirmed using both the entire sample, and only the youngest birth-cohort (all estimated coefficients P < 0.001).

CONCLUSION

A large increase in springtime solar insolation may impact the onset of bipolar disorder, especially with a family history of mood disorders. Recent societal changes that affect light exposure (LED lighting, mobile devices backlit with LEDs) may influence adaptability to a springtime circadian challenge.

International multi-site survey on the use of online support groups in bipolar disorder

BACKGROUND

Peer support is an established component of recovery from bipolar disorder, and online support groups may offer opportunities to expand the use of peer support at the patient's convenience. Prior research in bipolar disorder has reported value from online support groups.

AIMS

To understand the use of online support groups by patients with bipolar disorder as part of a larger project about information seeking.

METHODS

The results are based on a one-time, paper-based anonymous survey about information seeking by patients with bipolar disorder, which was translated into 12 languages. The survey was completed between March 2014 and January 2016 and included questions on the use of online support groups. All patients were diagnosed by a psychiatrist. Analysis included descriptive statistics and general estimating equations to account for correlated data.

RESULTS AND CONCLUSIONS

The survey was completed by 1222 patients in 17 countries. The patients used the Internet at a percentage similar to the general public. Of the Internet users who looked online for information about bipolar disorder, only 21.0% read or participated in support groups, chats, or forums for bipolar disorder (12.8% of the total sample). Given the benefits reported in prior research, clarification of the role of online support groups in bipolar disorder is needed. With only a minority of patients using online support groups, there are analytical challenges for future studies.

Internet use by patients with bipolar disorder: Results from an international multisite survey

There is considerable international interest in online education of patients with bipolar disorder, yet little understanding of how patients use the Internet and other sources to seek information. 1171 patients with a diagnosis of bipolar disorder in 17 countries completed a paper-based, anonymous survey. 81% of the patients used the Internet, a percentage similar to the general public. Older age, less education, and challenges in country telecommunications infrastructure and demographics decreased the odds of using the Internet. About 78% of the Internet users looked online for information on bipolar disorder or 63% of the total sample. More years of education in relation to the country mean, and feeling very confident about managing life decreased the odds of seeking information on bipolar disorder online, while having attended support groups increased the odds. Patients who looked online for information on bipolar disorder consulted medical professionals plus a mean of 2.3 other information sources such as books, physician handouts, and others with bipolar disorder. Patients not using the Internet consulted medical professionals plus a mean of 1.6 other information sources. The percentage of patients with bipolar disorder who use the Internet is about the same as the general public. Other information sources remain important.

Common use of dietary supplements for bipolar disorder: a naturalistic, self-reported study

Background

Dietary supplements are taken by about half of Americans. Knowledge of dietary supplement use is important because they may interact with prescription drugs or other supplements, cause adverse reactions including psychiatric symptoms, or contain inherently toxic ingredients or contaminants. This study explores the use of dietary supplements by patients with bipolar disorder in the US.

Methods

Data were obtained from an ongoing, naturalistic study of patients with bipolar disorder who received pharmacological treatment as usual. The patients self-reported their daily mood, sleep, and medications taken, including all drugs prescribed for bipolar disorder or that the patient felt impacted their mood. These included other prescribed drugs, over-the-counter drugs and dietary supplements. Drugs that received premarketing approval from the FDA were not included as dietary supplements. Patient demographics and daily medication use were characterized.

Results

Data were available from 348 patients in the US who returned a mean 249.5 days of data. In addition to prescribed psychiatric drugs, 101 of the 348 patients (29 %) used a dietary supplement for at least 7 days and 69 (20 %) used a supplement long term (for at least 50 % of days). Of the 101 supplement users, 72 (71.3 %) took one supplement daily. The 101 patients tried over 40 different supplements, and the long-term users took 19 different supplements. The most commonly taken supplements for both groups were fish oil, B vitamins, melatonin, and multivitamins. Patients using supplements were more likely to be white (p < 0.001), older (p = 0.009), and ill for more years (p = 0.025).

Conclusions

Many patients with bipolar disorder use dietary supplements in addition to prescribed drugs. Physicians should obtain detailed information about all dietary supplements taken by patients with bipolar disorder.

Relationship between sunlight and the age of onset of bipolar disorder: an international multisite study

BACKGROUND

The onset of bipolar disorder is influenced by the interaction of genetic and environmental factors. We previously found that a large increase in sunlight in springtime was associated with a lower age of onset. This study extends this analysis with more collection sites at diverse locations, and includes family history and polarity of first episode.

METHODS

Data from 4037 patients with bipolar I disorder were collected at 36 collection sites in 23 countries at latitudes spanning 3.2 north (N) to 63.4 N and 38.2 south (S) of the equator. The age of onset of the first episode, onset location, family history of mood disorders, and polarity of first episode were obtained retrospectively, from patient records and/or direct interview. Solar insolation data were obtained for the onset locations.

RESULTS

There was a large, significant inverse relationship between maximum monthly increase in solar insolation and age of onset, controlling for the country median age and the birth cohort. The effect was reduced by half if there was no family history. The maximum monthly increase in solar insolation occurred in springtime. The effect was one-third smaller for initial episodes of mania than depression. The largest maximum monthly increase in solar insolation occurred in northern latitudes such as Oslo, Norway, and warm and dry areas such as Los Angeles, California.

LIMITATIONS

Recall bias for onset and family history data.

CONCLUSIONS

A large springtime increase in sunlight may have an important influence on the onset of bipolar disorder, especially in those with a family history of mood disorders.

Influence of light exposure during early life on the age of onset of bipolar disorder

BACKGROUND

Environmental conditions early in life may imprint the circadian system and influence response to environmental signals later in life. We previously determined that a large springtime increase in solar insolation at the onset location was associated with a younger age of onset of bipolar disorder, especially with a family history of mood disorders. This study investigated whether the hours of daylight at the birth location affected this association.

METHODS

Data collected previously at 36 collection sites from 23 countries were available for 3896 patients with bipolar I disorder, born between latitudes of 1.4 N and 70.7 N, and 1.2 S and 41.3 S. Hours of daylight variables for the birth location were added to a base model to assess the relation between the age of onset and solar insolation.

RESULTS

More hours of daylight at the birth location during early life was associated with an older age of onset, suggesting reduced vulnerability to the future circadian challenge of the springtime increase in solar insolation at the onset location. Addition of the minimum of the average monthly hours of daylight during the first 3 months of life improved the base model, with a significant positive relationship to age of onset. Coefficients for all other variables remained stable, significant and consistent with the base model.

CONCLUSIONS

Light exposure during early life may have important consequences for those who are susceptible to bipolar disorder, especially at latitudes with little natural light in winter. This study indirectly supports the concept that early life exposure to light may affect the long term adaptability to respond to a circadian challenge later in life.

Antidepressant dosage taken by patients with bipolar disorder: factors associated with irregularity

BACKGROUND

This study analyzed regularity in the daily dosage of antidepressants taken by patients with bipolar disorder and identified the factors associated with irregularity.

METHODS

Daily self-reported medication dosage taken and mood ratings were available from 144 patients who received treatment as usual. All 144 patients took the same antidepressant for at least 100 days. One hundred eleven of these patients were also taking a mood stabilizer. Approximate entropy (ApEn) was used to measure serial regularity in daily dosage. Regularity is the tendency that values within a time series remain the same on incremental comparisons. Drug holidays (missing three or more consecutive days) were also determined. Generalized estimating equations (GEE) were used to estimate if any demographic or clinical variables were associated with regularity.

RESULTS

Although the mean percent of days missing doses was only 18.6%, there was a wide range of regularity in the daily antidepressant dosage. Drug holidays were common, occurring in 41% of the analyses. Factors significantly associated with irregularity were as follows: total number of psychotropic medications (p = 0.005), pill burden (p = 0.005), and depression (p = 0.015). Neither the percent of days missing doses nor the drug holidays were associated with any demographic or clinical factors. For patients taking both antidepressants and mood stabilizers, there was no significant difference in regularity in daily dosage between these drugs.

DISCUSSION

There can be considerable irregularity in daily dosage despite a low percent of days missing doses. Medication regimen complexity and depressed mood are associated with increased irregularity. Daily regularity in drug dosage may be more dependent on the individual than on the specific drug. Research on the clinical impact of irregularity in daily dosage of antidepressants is needed.

Regularity in daily mood stabilizer dosage taken by patients with bipolar disorder

OBJECTIVE

The aim of this study was to investigate regularity in the daily mood stabilizer dosage taken by patients with bipolar disorder, and identify factors associated with irregularity.

METHODS

Self-reported daily mood and medication data were available from 206 patients who took the same mood stabilizer for ≥100 days. Approximate entropy (ApEn) was used to measure serial regularity in daily mood stabilizer dosage. Generalized estimating equations (GEE) were used to estimate if demographic or clinical variables were associated with ApEn.

RESULTS

There was a wide range of regularity in the daily mood stabilizer dosage. The mean percent of days of missing doses was 13.6%. The number of psychotropic medications (p=0.007), pill burden (p=0.004) and percent of days with depressed mood (p=0.013) were associated with more irregularity, while the percent of days euthymic (p=0.014) was associated with less irregularity. The percent of days missing doses was not associated with the number of medications, pill burden or mood ratings.

DISCUSSION

Patients may have irregularity in daily dosage in spite of a low percent of days missing doses. Psychotropic medication regimen complexity and depression are associated with increased dosage irregularity. Research is needed on how irregularity in daily dosage impacts the continuity of drug action of mood stabilizers.

Drug treatment patterns in bipolar disorder: analysis of long-term self-reported data

Background

The objective of this study is to investigate drug treatment patterns in bipolar disorder using daily data from patients who received treatment as usual.

Methods

Patients self-reported the drugs taken daily for about 6 months. Daily drug use and drug combinations were determined for each patient, both by the specific drugs and by medication class. The drug load was calculated for all drugs taken within a medication class.

Results and discussion

Four hundred fifty patients returned a total of 99,895 days of data (mean 222.0 days). The most frequently taken drugs were mood stabilizers. Of the 450 patients, 353 (78.4%) took a stable drug combination for ≥50% of days. The majority of patients were taking polypharmacy, including 75% of those with a stable combination. Only a small number of drugs were commonly taken within each medication class, but there were a large number of unique drug combinations: 52 by medication class and 231 by specific drugs. Eighty percent of patients with a stable combination were taking three or less drugs daily. Patients without a stable combination took drugs but made frequent changes. Taking more than one drug within a medication class greatly increased the drug load.

To summarize, (1) patients were more likely to take a mood stabilizer than any other drug; (2) although most patients were taking polypharmacy, there were no predominant drug regimens even among those taking a stable combination; and (3) most patients with a stable combination take a relatively small number of drugs daily. The wide variation in drug regimens and numerous possible drug combinations suggest that more evidence is needed to optimize treatment of bipolar disorder.

Impact of sunlight on the age of onset of bipolar disorder

OBJECTIVE

Although bipolar disorder has high heritability, the onset occurs during several decades of life, suggesting that social and environmental factors may have considerable influence on disease onset. This study examined the association between the age of onset and sunlight at the location of onset.

METHOD

Data were obtained from 2414 patients with a diagnosis of bipolar I disorder, according to DSM-IV criteria. Data were collected at 24 sites in 13 countries spanning latitudes 6.3 to 63.4 degrees from the equator, including data from both hemispheres. The age of onset and location of onset were obtained retrospectively, from patient records and/or direct interviews. Solar insolation data, or the amount of electromagnetic energy striking the surface of the earth, were obtained from the NASA Surface Meteorology and Solar Energy (SSE) database for each location of onset.

RESULTS

The larger the maximum monthly increase in solar insolation at the location of onset, the younger the age of onset (coefficient= -4.724, 95% CI: -8.124 to -1.323, p=0.006), controlling for each country's median age. The maximum monthly increase in solar insolation occurred in springtime. No relationships were found between the age of onset and latitude, yearly total solar insolation, and the maximum monthly decrease in solar insolation. The largest maximum monthly increases in solar insolation occurred in diverse environments, including Norway, arid areas in California, and Chile.

CONCLUSION

The large maximum monthly increase in sunlight in springtime may have an important influence on the onset of bipolar disorder.

Association between age of onset and mood in bipolar disorder: comparison of subgroups identified by cluster analysis and clinical observation

BACKGROUND

This study compared subgroups identified by cluster analysis and clinical observation by evaluating the association between the age of onset of bipolar disorder and self-reported daily mood ratings.

METHODS

Two hundred and seventy patients with bipolar disorder provided daily self-reported mood ratings for about 6 months returning 55,188 days of data. The age of onset subgroups were determined both using previously defined cutoff values based upon clinical observation (≤12 years, 13-19 years, 20-29 years, >29 years), and model-based cluster analysis. Demographic characteristics were compared in the age of onset subgroups. Univariate general linear models with age of onset subgroups and other demographic variables as fixed factors and covariates were used to analyze the percent of days depressed, euthymic and hypomanic/manic.

RESULTS

Using the predetermined subgroups, demographic differences were found between the four subgroups in the diagnosis of bipolar I/II, years of illness, age and use of lamotrigine. Post-hoc pairwise comparison found that patients with an age of onset less ≤ 12 years spent more days hypomanic/manic: 16.4 percent versus 8.0 for patients with an age of onset between 13 and 19 years (p=0.006) and 8.2 percent for patients with an age of onset between 20 and 29 years (p = 0.031). The majority of the additional days of hypomania/mania occurred outside of an episode. Model-based cluster analysis found a mixture of 2 distributions of onset with peaks at age 15.1 years (SD = 4.7) and 27.5 years (SD = 10.2). Analysis of these two subgroups detected no significant differences in demographic characteristics or mood ratings.

CONCLUSION

Age of onset subgroups arising from clinical observation may be more useful than those determined by cluster analysis.

Using 'stall detection' as an auxiliary mechanism for sensing obstacles and hand grasping in arm prosthesis

This paper proposes a novel method for sensing obstacles and hand grasping activities in electromechanical arm prosthesis. The described method is based on indirectly sensing 'Stall' condition in prosthesis actuators through hall-effect sensors already embedded on its dc motors, thus not requiring external sensors. To test the proposed methodology, an electromechanical arm prosthesis of 3 degrees of freedom (DOF), plus 'open-close' of hand, which is being developed at CINVESTAV Mexico, was used. At the end of this paper, experimental measurements performed on the tested prosthesis, using and non using 'Stall Detection', are shown. We demonstrated that methodology can be used successfully for "sensing obstacles", but it cannot be used alone for "hand grasping". In any case, this technique demonstrated to be a good method to simplify and strengthen control of prosthesis.

Sexual risk behaviour and its determinants among men who have sex with men in Catalonia, Spain

To evaluate the prevalence of sexual risk behaviours among men who have sex with men (MSM) in Catalonia and to identify sociodemographic, psychosocial, and behavioural factors associated with unprotected anal intercourse (UAI) with casual partners a convenience sample of 850 MSM was recruited in 2006. An anonymous questionnaire was used to explore risk behaviours during the previous 12 months. Logistic regression models were used to examine the variables associated with UAI. Mean age was 41 years and 20.4% were immigrants. Among those with casual partners (91.7% of all respondents), 31.4% had UAI. The multivariate analysis revealed that the likelihood of UAI was higher in men who were HIV-positive (OR: 1.77), used more than four drugs before sex (OR: 4.90 for +6), were not from Spain (OR: 2.10 for Latin American; OR: 1.86 for other immigrants), had more than 20 sexual partners (OR: 1.56), met casual sex partners on the Internet (OR:1.45) and presented a high level of internalised homophobia (OR: 2.40). HIV/STI prevention programmes for MSM in Catalonia should incorporate activities that strengthen self-esteem, take into account the impact of internalised homophobia, and adapt to the sociocultural reality of immigrants. Furthermore, these programmes should also address substance abuse and alert HIV-positive men about the risk of HIV re-infection and transmission of other STI.

The serotonin transporter 5-HTTPR polymorphism is associated with current and lifetime depression in persons with chronic psychotic disorders

OBJECTIVE

Variation in the serotonin transporter gene (SLC6A4) promoter region has been shown to influence depression in persons who have been exposed to a number of stressful life events.

METHOD

We evaluated whether genetic variation in 5-HTTLPR, influences current depression, lifetime history of depression and quantitative measures of depression in persons with chronic psychotic disorders. This is an association study of a genetic variant with quantitative and categorical definitions of depression conducted in the southwest US, Mexico and Costa Rica. We analyzed 260 subjects with a history of psychosis, from a sample of 129 families.

RESULTS

We found that persons carrying at least one short allele had a statistically significant increased lifetime risk for depressive syndromes (P < 0.02, odds ratio 2.18, 95% CI 1.10-4.20).

CONCLUSION

The 'ss' or 'sl' genotype at the 5-HTTLPR promoter polymorphic locus increases the risk of psychotic individuals to develop major depression during the course of their illness.

The epsin 4 gene is associated with psychotic disorders in families of Latin American origin

This study attempted to replicate evidence for association of the Epsin 4 gene (which encodes enthoprotin, a protein involved in vesicular transport) to schizophrenia in a new sample of families segregating schizophrenia drawn from the Latin American population. 1,423 subjects (767 with a history of psychosis) from 337 Latino families were genotyped using three single nucleotide polymorphisms (SNPs) spanning the Epsin 4 gene. A family based association test was utilized to test for association of these SNPs to the phenotypes of psychosis and schizophrenia. Haplotypes defined by these three SNPs showed significant association to the phenotype of psychosis in this sample (global p value=0.014, bi-allelic p value=0.047). Variation in the Epsin 4 gene is significantly associated with psychotic disorder in this Latino population. This provides additional support for the involvement of enthoprotin in the pathogenesis of schizophrenia and other psychotic disorders.

Long-term tolerability and effectiveness of duloxetine in the treatment of major depressive disorder

To examine the long-term safety, tolerability, and effectiveness of duloxetine in the treatment of major depressive disorder in a naturalistic study design meant to mimic clinical practice. Data were from the long-term, open-label, extension phase that followed a 12-week acute-treatment, multicenter study of adult outpatients with major depressive disorder. After the first week of the acute phase, all patients were treated with at least 60 mg daily duloxetine, which could be titrated to a maximum dose of 120 mg daily. Outcome measures were collected at monthly visits and included spontaneously reported adverse events, weight, vital signs, and the 17-item Hamilton Depression Rating scale. Seventy-two of the 177 (40.7%) patients who entered the extension phase of this study completed the study. The mean duration of participation in the extension was 305 days, with total exposure ranging from 68 to 707 days. Of the 177 patients who entered the extension, only 12 or 13 (7.0%) showed clinically significant worsening of depression that led to study discontinuation. The mean 17-item Hamilton Depression Rating scale score remained below 7 throughout the extension. A total of 21/177 patients (11.9%) discontinued due to adverse events during extension treatment. The adverse events causing discontinuation during the extension, with the exception of weight gain, were generally not unique to the extension phase, with 11/21 patients (52.0%) discontinuing due to adverse events that were first reported during acute treatment. Weight gain was reported as a reason for discontinuation during extension treatment in 4/177 (2.3%) patients. In this open-label study, efficacy was maintained for most patients. The adverse events causing discontinuation during the extension phase were generally not unique to the extension phase. Few patients experienced significant weight gain.

Genetic structure analysis of three Hispanic populations from Costa Rica, Mexico, and the southwestern United States using Y-chromosome STR markers and mtDNA sequences

Two hundred seventeen male subjects from Costa Rica, Mexico, and the Hispanic population of the southwestern United States were studied. Twelve Y-chromosome STRs and the HVSI sequence of the mtDNA were analyzed to describe their genetic structure and to compare maternal and paternal lineages. All subjects are part of two NIMH-funded studies to localize schizophrenia susceptibility genes in Hispanic populations of Mexican and Central American ancestry. We showed that these three populations are similar in their internal genetic characteristics, as revealed by analyses of mtDNA and Y-chromosome STR diversity. These populations are related through their maternal lineage in a stronger way than through their paternal lineage, because a higher number of shared haplotypes and polymorphisms are seen in the mtDNA (compared to Y-chromosome STRs). These results provide evidence of previous contact between the three populations and shared histories. An analysis of molecular variance revealed no genetic differentiation for the mtDNA for the three populations, but differentiation was detected in the Y-chromosome STRs. Genetic distance analysis showed that the three populations are closely related, probably as a result of migration between close neighbors, as indicated by shared haplotypes and their demographic histories. This relationship could be an important common feature for genetic studies in Latin American and Hispanic populations.

A genome-wide scan for schizophrenia and psychosis susceptibility loci in families of Mexican and Central American ancestry

Schizophrenia is a complex psychiatric disorder, likely to be caused in part by multiple genes. In this study, linkage analyses were performed to identify chromosomal regions most likely to be associated with schizophrenia and psychosis in multiplex families of Mexican and Central American origin. Four hundred and fifty-nine individuals from 99 families, containing at least two siblings with hospital diagnoses of schizophrenia or schizoaffective disorder, were genotyped. Four hundred and four microsatellite markers were genotyped for all individuals and multipoint non-parametric linkage analyses were performed using broad (any psychosis) and narrow (schizophrenia and schizoaffective disorder) models. Under the broad model, three chromosomal regions (1pter-p36, 5q35, and 18p11) exhibited evidence of linkage with non-parametric lod (NPL) scores greater than 2.7 (equivalent to empirical P values of less than 0.001) with the peak multipoint NPL = 3.42 (empirical P value = 0.00003), meeting genomewide evidence for significant linkage in the 1pter-p36 region. Under the narrow model, the same three loci showed (non-significant) evidence of linkage. These linkage findings (1pter-p36, 18p11, and 5q35) highlight where genes for psychosis and schizophrenia are most likely to be found in persons of Mexican and Central American ancestry, and correspond to recent linkages of schizophrenia or psychosis in other populations which were formed in part from emigrants from the Spanish empire of the 15th and 16th centuries.

[Fatal familiar insomnia: clinical, neurophysiological and histopathological study of two cases]

INTRODUCTION

Family prion diseases are caused by mutations in the gene coding the prion protein (PrP), originating an altered isoform called prion. One of the most uncommon is the fatal familial insomnia (FFI), an entity characterized by sleep disorders and that is associated to a mutation in codon 178.

METHODS

We have studied two male patients, aged 43 and 49 years respectively, from the same family.

RESULTS

The most significant symptoms were sleep disorders with agitation, fractionated sleep, snoring and daytime sleepiness. The evolution was brief, the patient dying at a few months of the clinical debut. Sleep registries showed destructuration with total loss of the normal cycle of the phases and great decrease of the sleep spindles and K complexes in both cases. The polygraphy showed tachycardia and apnea pauses. In the molecular study, a mutation in the codon 178 was detected, both being methionine/methionine homozygotes at position 129. The most outstanding neuropathological abnormalities were located in the thalamus with gliosis and neuronal loss of anterior and dorsomedial ventral nuclei and also intense neuronal loss in olive of the first case.

CONCLUSIONS

This study describes two new cases of FFI with genotype D178N-129M and short course classical phenotype. The polysomnography is essential in the diagnostic strategy of this disease whose neuropathological substrate is the thalamic alterations and of the inferior olive. Molecular biology permits an exact diagnosis of FFI although there is still controversy on the phenotypal variability and physiopathogenic mechanisms.

The human oncoprotein MDM2 uses distinct strategies to inhibit transcriptional activation mediated by the wild-type p53 and its tumor-derived mutants

Human MDM2 (hMDM2) inhibits transcriptional activation mediated by wild-type p53 and its tumor-derived mutants. We present evidence to show that hMDM2 interacts with the tumor-derived mutants of p53 and inhibits transcriptional activation of the human c-myc promoter mediated by the tumor-derived mutants of p53 through two domains. These two domains of hMDM2 are able to function independent of each other. Interaction with either of the domains is sufficient for inhibition of mutant p53-mediated transactivation. One of these domains is the same as the wild-type p53 interaction domain of hMDM2, whereas a second domain is situated within amino acid 190 and 276 residues and is specific for mutant p53. hMDM2 does not inhibit transcriptional activation mediated by the transcriptional activator VP16, suggesting that the inhibition is not mediated by inactivation of a general transcription factor. The transactivation and the oligomerization domains of mutant p53 are dispensable for its interaction with hMDM2. Thus, both hMDM2 and p53 recognize each other through unique domains. These observations suggest that forms of hMDM2 incapable of interacting with the wild-type p53, and are often expressed in transformed cells, would inhibit mutant p53-mediated transactivation and antagonize the tumorigenic function of mutant p53. This inhibitory function of hMDM2 may account for infrequent co-occurrence of p53 mutation and hMDM2 overexpression in cancer cells. Our results also suggest distinct mechanisms for wild-type and mutant p53-mediated transcriptional activation.

Whole blood ionized magnesium: age-related differences in normal values and clinical implications of ionized hypomagnesemia in patients undergoing surgery for congenital cardiac disease

OBJECTIVES

We sought to (1) determine reference values for whole blood ionized magnesium concentrations in newborns, children, and young adults and (2) evaluate the frequency and clinical implications of ionized hypomagnesemia in patients undergoing surgery for congenital heart disease.

METHOD

We prospectively measured ionized magnesium concentrations in 299 subjects (113 control subjects and 186 patients undergoing surgery for congenital heart disease). Subjects were categorized by age. In the surgical group blood samples were obtained before bypass, during bypass (cooling and rewarming), after bypass, and during admission to the intensive care unit. Ionized hypomagnesemia was defined as ionized magnesium level 2 standard deviations below the mean of control subjects in the same age group. Patients were analyzed, controlling for cardiopulmonary bypass time.

RESULTS

In the control group ionized magnesium concentrations differed by age. Neonates and adults showed lower ionized magnesium concentrations compared with those of other age groups. Infants exhibited the highest ionized magnesium concentration. In the surgical group patients older than 1 month showed a higher proportion of ionized hypomagnesemia compared with that found in neonates at baseline (P <.001), after bypass (P =. 03), and at admission to the intensive care unit (P =.02). Controlling for cardiopulmonary bypass time, patients older than 1 month who were hypomagnesemic during bypass showed longer intubation time (P =.001) and longer intensive care stay (P =.01) and tended to have a higher pediatric severity of illness score on intensive care admission (P =.14) compared with patients without ionized hypomagnesemia.

CONCLUSIONS

There are age-related differences in normal ionized magnesium concentrations. Ionized hypomagnesemia is a common and clinically relevant occurrence among patients older than 1 month of age undergoing surgery for congenital heart disease.

Beta-Lactam antibiotic resistance in gram-positive bacterial pathogens of the upper respiratory tract: a brief overview of mechanisms

Streptococcus pneumoniae and Group A Streptococci are frequent colonizers and major causative agents of disease in the upper respiratory tract of humans. In spite of the immense and common selective pressure of beta-lactam antibiotics against both of these bacterial species during the last four to five decades, penicillin-resistant strains of group A streptococci have not been described in the clinical literature as of 1994. This is particularly puzzling since penicillin-resistant mutants of this bacterium have been isolated repeatedly in the laboratory and such mutants carry altered penicillin-binding proteins (PBPs) with reduced drug affinities, i.e., a basic mechanism identical to the one seen in penicillin-resistant isolates of Streptococcus pneumoniae that have emerged in large numbers and at numerous locations and have spread explosively all over the globe by the beginning of the 1990s. The reasons for this contrasting situation are not clear. In Streptococcus pneumoniae the resistance mechanism to penicillin appears to originate in recombinational events between ancestral pneumococcal cells and as yet unidentified extra species DNA donors and probably involves the process of genetic transformation for which this bacterium has a remarkable hormonally controlled mechanism. The integration of foreign DNA sequences in the pneumococcal PBP genes leads to the remodeling of at least four of the five PBPs that change in their kinetic properties and increase in the penicillin resistance level of the bacteria also seems to involve increased production of the low-affinity binding proteins.

Reconstruction of 3-dimensional right ventricular shape and volume from 3 orthogonal planes

This study validates a reconstructive technique that describes 3-dimensional right ventricular (RV) shape and volume with the use of 3 standard echocardiographic planes. The volume of 24 cast models of lamb right ventricles (12 normal, 12 hypertensive) was determined by water displacement. Reconstruction of the cast shapes was calculated from 2 sets of digitized data: cast cross-sectional digitized tracings and echocardiographic cross-sectional tracings. Regional volume ratios from both data sets were assessed to quantitatively specify RV regional volume differences between normotensive and hypertensive right ventricles. This method described the 3-dimensional RV shape with no differences between reconstructed volumes and true volumes for either normotensive or hypertensive casts. Between hypertensive and normal groups, regional volume ratios yielded a difference in free wall ratios that was observed to be greater in the hypertensive cast group (P =.007).

Changes in whole blood lactate levels during cardiopulmonary bypass for surgery for congenital cardiac disease: an early indicator of morbidity and mortality

OBJECTIVE

Our objective was to evaluate the change in lactate level during cardiopulmonary bypass and the possible predictive value in identifying patients at high risk of morbidity and mortality after surgery for congenital cardiac disease.

METHODS

We prospectively studied lactate levels in 174 nonconsecutive patients undergoing cardiopulmonary bypass during operations for congenital cardiac disease. Arterial blood samples were taken before cardiopulmonary bypass, during cardiopulmonary bypass (cooling and rewarming), after cardiopulmonary bypass, and during admission to the cardiac intensive care unit. Complicated outcomes were defined as open sternum as a response to cardiopulmonary instability, renal failure, cardiac arrest and resuscitation, extracorporeal membrane oxygenation, and death.

RESULTS

The largest increment in lactate level occurred during cardiopulmonary bypass. Lactate levels decreased between the postbypass period and on admission to the intensive care unit. Patients who had circulatory arrest exhibited higher lactate levels at all time points. Nonsurvivors had higher lactate levels at all time points. A change in lactate level of more than 3 mmol/L during cardiopulmonary bypass had the optimal sensitivity (82%) and specificity (80%) for mortality, although the positive predictive value was low.

CONCLUSIONS

Hyperlactatemia occurs during cardiopulmonary bypass in patients undergoing operations for congenital cardiac disease and may be an early indicator for postoperative morbidity and mortality.