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.

Brain age in bipolar disorders: Effects of lithium treatment

OBJECTIVE

Bipolar disorders increase the risk of dementia and show biological and brain alterations, which resemble accelerated aging. Lithium may counter some of these processes and lower the risk of dementia. However, until now no study has specifically investigated the effects of Li on brain age.

METHODS

We acquired structural magnetic resonance imaging scans from 84 participants with bipolar disorders (41 with and 43 without Li treatment) and 45 controls. We used a machine learning model trained on an independent sample of 504 controls to estimate the individual brain ages of study participants, and calculated BrainAGE by subtracting chronological from the estimated brain age.

RESULTS

BrainAGE was significantly greater in non-Li relative to Li or control participants, F(2, 125) = 10.22, p < 0.001, with no differences between the Li treated and control groups. The estimated brain age was significantly higher than the chronological age in the non-Li (4.28 ± 6.33 years, matched t(42) = 4.43, p < 0.001), but not the Li-treated group (0.48 ± 7.60 years, not significant). Even Li-treated participants with partial prophylactic treatment response showed lower BrainAGE than the non-Li group, F(1, 64) = 4.80, p = 0.03.

CONCLUSIONS

Bipolar disorders were associated with greater, whereas Li treatment with lower discrepancy between brain and chronological age. These findings support the neuroprotective effects of Li, which were sufficiently pronounced to affect a complex, multivariate measure of brain structure. The association between Li treatment and BrainAGE was independent of long-term thymoprophylactic response and thus may generalize beyond bipolar disorders, to neurodegenerative disorders.

Long term vascular complications of Coxiella burnetii infection in Switzerland: cohort study

OBJECTIVE

To evaluate the range of long term vascular manifestations of Coxiella burnetii infection.

DESIGN

Cohort study in Switzerland of people affected in 1983 by the largest reported outbreak of Q fever and who were followed up 12 years later. Follow up information about possible vascular disease and endocarditis was obtained through a mailed questionnaire and death certificates.

SETTING

Val de Bagnes, a rural Alpine valley in Switzerland.

PARTICIPANTS

2044 (87%) of 2355 people who had serum testing for Coxiella burnetii infection in 1983: 1247 were classed as not having been infected, 411 were classed as having been acutely infected, and 386 were classed as having been infected before 1983.

MAIN OUTCOME MEASURES

Relative risk controlled for age and sex and 12 year risk of vascular diseases and endocarditis among infected participants as compared with those who had never been infected.

RESULTS

The 12 year risk of endocarditis or venous thromboembolic disease was not increased among those who had been acutely infected. The 12 year risk of arterial disease was significantly higher among those who had been acutely infected (7%) as compared with those who had never been infected (4%) (relative risk 2.2, 95% confidence interval 1.4 to 3.6). Specifically, there was an increased risk of developing a cerebrovascular accident (relative risk 3.7, 1.6 to 8.4) and cardiac ischaemia (relative risk 1.9, 1.04 to 3.4). 12 year mortality was significantly higher among the 411 people who had been acutely infected in 1983 (9.7%; age adjusted relative risk 1.8, 1.2 to 2.6) when compared with the 1247 participants who had remained serologically negative in 1983 (7.0%).

CONCLUSIONS

Coxiella burnetii infection may cause long term complications including vascular disease.

A new case of myelodysplastic syndrome with 6p rearrangement

Bone marrow cells from a patient with refractory anemia with ringed sideroblasts were studied cytogenetically. All metaphases analyzed revealed an abnormal karyotype with complex defects. The most prominent defect consisted of a rearrangement of the short arm of chromosome 6. Until now, 6p rearrangements have been preferentially observed in myelodysplastic patients with a history of previous exposure to toxic products such as alkylating agents or environmental factors of occupational origin. Although our patient was not exposed to alkylating agents, for about 20 years he has regularly consumed important quantities of analgesics, tranquilizers, and nonsteroidal antiinflammatory drugs. The eventual relationship between sideroblastic anemia and drug abuse, as well as the existence of chromosome sites preferentially rearranged in the bone marrow cells of myelodysplastic patients, are discussed.

Cerebral blood flow in humans following resuscitation from cardiac arrest

Cerebral blood flow was measured by xenon-133 washout in 13 patients 6-46 hours after being resuscitated from cardiac arrest. Patients regaining consciousness had relatively normal cerebral blood flow before regaining consciousness, but all patients who died without regaining consciousness had increased cerebral blood flow that appeared within 24 hours after resuscitation (except in one patient in whom the first measurement was delayed until 28 hours after resuscitation, by which time cerebral blood flow was increased). The cause of the delayed-onset increase in cerebral blood flow is not known, but the increase may have adverse effects on brain function and may indicate the onset of irreversible brain damage.

[Bernard-Soulier syndrome in a Swiss family]

We report the case of a 38-year-old woman with hemorrhagic diathesis. Since early childhood she has suffered from epistaxis, gingival bleeding, ecchymoses and, since puberty, very frequent menorrhagia. Prolongation of bleeding time and thrombocytopenia (100,000 platelets/microliter) with giant platelets were observed. Since idiopathic thrombopenic purpura was suspected, splenectomy was performed. Neither this nor steroid treatment caused any improvement. The patient was able to give birth to an unaffected child, but delivery was followed by a major hemorrhage. In 1986, hysterectomy was considered because of frequent menorrhagia and, therefore, the patient's hemostasis was reinvestigated. The aforementioned abnormalities were confirmed and complementary examinations by electron microscope revealed giant platelets without granular abnormalities. While von Willebrand factor was normal, ristocetin agglutination was defective and analysis of platelet membrane glycoproteins showed absence of glycoprotein Ib. - These observations prompted the diagnosis of Bernard-Soulier syndrome. The study of the family demonstrated that 6 family members were heterozygote. This is believed to be the first large Bernard-Soulier family reported in Switzerland.

An important outbreak of human Q fever in a Swiss Alpine valley

We describe an important Q fever human epidemic involving 415 serologically confirmed cases in the Val de Bagnes (Valais, Switzerland) during the autumn of 1983. The ages of the 415 cases with acute Q fever ranged from 8 to 82 years with a mean of 35 years, of whom 58% (240) were men and 42% (175) were women. This outbreak started about three weeks after 12 flocks of sheep (between 850 and 900 animals) descended from the alpine pastures to the valley. Geographically, the epidemic reached all the villages in the lower part of the Val de Bagnes located along the road followed by the sheep. As a result, 21.1% of the population of these villages contracted Q fever during this period. In contrast (p less than 0.001), the inhabitants of the higher villages away from the road followed by the sheep were only slightly affected (2.9%). Better collaboration between physicians and veterinarians would prevent such outbreaks in the future.

[Clinical aspects observed during an epidemic of 415 cases of Q fever]

The clinical findings during a major epidemic of Q-fever which affected 415 people in the Val de Bagnes (Valais, Switzerland) in the autumn of 1983 are reported. Q-fever symptoms were evident in 191 cases but inconspicuous or absent in 224 cases. The symptoms most frequently reported were prolonged high fever, headaches, severe exhaustion, loss of appetite, cough and myalgia. Amongst disorders which accompany acute Q-fever, pneumonia and granulomatous hepatitis are very frequent, while myopericarditis and glomerulonephritis are less frequently observed. Endocarditis, a later complication of Q-fever, is a severe illness which more frequently affects patients with underlying valvular lesions. New serological techniques now permit more rapid and more accurate diagnosis of both acute and chronic Q-fever.

[IgA deficiency and Addison's disease]

A case of Addison's disease and selective IgA deficiency in a 15-year-old male is discussed. The etiology of Addison's disease in this case is unknown. Investigation of HLA-antigens in the family does not yield the usual pattern of autoimmune diseases. Nevertheless, this very rare association does not appear to be fortuitous.