Chronic obstructive pulmonary disease burden, grades and erythrocytosis at a tertiary hospital in western Uganda.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide among people over 40 years of age, and erythrocytosis is one of the major complications associated with increased mortality among COPD patients. The study aimed to determine the proportion of COPD, associated factors, and the burden of erythrocytosis among COPD participants. METHODS AND MATERIALS: A descriptive cross-sectional study design was used. A consecutive sampling technique was used to obtain study participants at the Fort Portal Regional Referral Hospital outpatient clinic. Focused history and physical examination were carried out to select eligible participants. Participants were screened using the COPD population screener for spirometry after consenting to participate. The study enrolled all adults at risk of having COPD based on the COPD population screener and able to undergo spirometry. Spirometry was carried out according to the Global Chronic Obstructive Lung Disease and European Respiratory Society guidelines, and haemoglobin concentration was measured. RESULTS: One hundred eighty participants were enrolled in the study, most of whom were females. The modal and mean age of participants was 60 years with 139 (77.2%) females and primary as the highest education level 149(82.8%). The proportion of COPD was 25% (45) [95% CI 18.9 - 32] and highest among females (68.9%) and those aged 60 years and above (70%). The combined COPD assessment tool groups had a proportion of 55.6%, 37.8%, 4.4%, and 2.2% for groups A, B, C, and D, respectively. Age < 50 years was protective against COPD, while for every additional year of smoking, there was an associated 6.5% increased risk compared to the general population. Additionally, the proportion of erythrocytosis among COPD participants was 6.7%. CONCLUSIONS AND RECOMMENDATIONS: There was a high proportion of COPD among study participants (25%), with a 6.7% proportion of erythrocytosis. We recommend a complete blood count for every patient in groups C and D of the ABCD COPD GOLD groups.

Neonatal polycythemia: prevalence, risk factors and predictors of severity.

BACKGROUND: Polycythemia is a disorder with several causes and risk factors. The clinical presentation is variable, ranging from asymptomatic newborns to cases with severe physiological changes. The aim of this study was to assess the prevalence, risk factors and predictors of severity of polycythemia in a Portuguese level III Neonatal Intensive Care Unit (NICU). METHODS: Case-control study of all term newborns with the diagnosis of polycythemia admitted to the NICU of the São João Universitary Hospital Center, Porto, Portugal, from January 1, 1999 to December 31, 2019; and who met one of the following inclusion criteria were eligible for the study: 1) Hct>65% or Hb>22 g/dL; and 2) Hb≥21 g/dL with clinical manifestations of polycythemia. RESULTS: A total of 53 newborns fulfilled the inclusion criteria and were included in the study, corresponding to a prevalence of 0.57%. Birth outside the hospital was the only risk factor with statistical significance. Of 53 cases, 51 (96.23%) had symptomatic polycythemia. The most frequent symptoms were: hyperbilirubinemia (69.81%), hypoglycemia (52.83%), thrombocytopenia (50.94%), cardiorespiratory (33.96%), and neurological symptoms (33.96%). Of the 53 newborns evaluated, 41 (77.36%) needed treatment. The only risk factors that influenced the hematocrit value were maternal diabetes and fetal growth restriction. CONCLUSIONS: The best way to improve the prognosis of polycythemia is to identify the risk factors present throughout pregnancy and make an early diagnosis and treatment. Out-of-hospital births should be avoided. The diagnosis should not be excluded, even if hemoglobin and hematocrit are within normal limits.

Erythrocytosis in Gender-Affirming Care With Testosterone.

PURPOSE: Gender-affirming hormone therapy (GAHT) is safe overall, with few adverse effects. One potential effect from using testosterone for GAHT is an increase in hemoglobin and/or hematocrit, known as secondary erythrocytosis. Current guidelines recommend monitoring hemoglobin or hematocrit routinely in the first year, some as frequently as every 3 months, which can create barriers to care. Our study explored the incidence of erythrocytosis in the first 20 months of testosterone therapy among people receiving gender-affirming care. METHODS: This is a descriptive fixed cohort study of hematocrit and hemoglobin data from the charts of 282 people taking testosterone for GAHT. RESULTS: During the first 20 months of testosterone therapy, the cumulative incidence of hematocrit >50.4% was 12.6%, hematocrit >52% was 1.0%, and hematocrit >54% was 0.6%. All people were taking injectable testosterone cypionate, with a median dose of 100 mg weekly. CONCLUSION: Severe erythrocytosis (hematocrit >54%) is a rare outcome of gender-affirming testosterone therapy. Clinical recommendations should reconsider the need for routine frequent erythrocytosis screening within the first year of testosterone therapy for patients who prefer to minimize laboratory draws.

Selective intrauterine growth restriction without concomitant twin-to-twin transfusion syndrome, natural history, and risk factors for fetal death: A systematic review and meta-analysis.

OBJECTIVE: This study aimed to evaluate the natural history of selective intrauterine growth restriction in monochorionic twin pregnancies based on the Gratacós classification, including progression of, improvement in, or stability of umbilical artery Dopplers and progression to twin-to-twin transfusion syndrome or twin anemia polycythemia syndrome. We also aimed to investigate risk factors for smaller twin demise. DATA SOURCES: A systematic search was performed to identify relevant studies published in English up to June 2022 using the databases PubMed, Scopus, and Web of Science STUDY ELIGIBILITY: We used retrospective and prospective studies published in English that reported on selective intrauterine growth restriction without concomitant twin-to-twin transfusion syndrome. STUDY APPRAISAL AND SYNTHESIS METHODS: Articles that investigated selective intrauterine growth restriction progression and outcomes by umbilical artery Doppler end-diastolic flow (Gratacós classification) were included. Type I included selective intrauterine growth restriction cases with positive end-diastolic flow, type II included those cases with persistently absent end-diastolic flow, and type III included cases with intermittent absent or reversed end-diastolic flow. Pregnancies in which a diagnosis of twin-to-twin transfusion syndrome or twin anemia polycythemia sequence was made before the diagnosis of selective intrauterine growth restriction were not included in the analysis. A random effects model was used to pool the odds ratios and the corresponding 95% confidence intervals. Heterogeneity was assessed using the I2 value. RESULTS: A total of 17 studies encompassing 2748 monochorionic pregnancies complicated by selective intrauterine growth restriction were included in the analysis. The incidence of stable, deteriorating, or improving umbilical artery Dopplers in type I cases was 68% (95% confidence interval, 26-89), 23% (95% confidence interval, 7-40), and 9% (95% confidence interval, 0.0-100), respectively. In type II cases, the incidence was 40% (95% confidence interval, 18-81), 50% (95% confidence interval, 23-82), and 10% (95% confidence interval, 4-37), respectively, and in type III cases, the incidence was 55% (95% confidence interval, 2-99), 23% (95% confidence interval, 9-43), and 22% (95% confidence interval, 6-54), respectively. The risk for progression to twin-to-twin transfusion syndrome was comparable between type I (7%) and type III (9%) cases and occurred in 4% (95% confidence interval, 0-67) of type II cases with no significant subgroup differences. Progression to twin anemia polycythemia syndrome was highest in type I cases (12%) and comparable between type II (2%) and III (1%) cases with no significant subgroup differences. Risk factors for smaller twin demise were earlier gestational age at diagnosis (mean difference, -2.69 weeks; 95% confidence interval, -4.94 to -0.45; I2, 45%), larger intertwin weight discordance (mean difference, 34%; 95% confidence interval, 1.35-5.38; I2, 28%), deterioration of umbilical artery Dopplers for each of type II and III cases (odds ratio, 3.05; 95% confidence interval, 1.36-6.84; I2, 24%; and odds ratio, 4.5; 95% confidence interval, 2.31-8.77; I2, 0.0%, respectively), and absent or reversed ductus venosus a-wave for each of type II and III cases (odds ratio, 3.35; 95% confidence interval, 2.28-4.93; I2, 0.0%; and odds ratio, 2.36; 95% confidence interval, 1.08-5.13; I2, 0.0%, respectively). Progression to twin-to-twin transfusion syndrome was not significantly associated with smaller twin demise for each of type II and III selective intrauterine growth restriction cases. CONCLUSION: These findings improve our understanding of the natural history of the types of selective intrauterine growth restriction and of the predictors of smaller twin demise in type II and III selective intrauterine growth restriction cases. The current data provide vital counseling points and support the need for modifications of the current selective intrauterine growth restriction classification system to include the variations in umbilical artery and ductus venosus Dopplers to better identify a cohort that might benefit from fetal intervention for which future multicenter prospective randomized trials are needed.

Is Erythrocytosis More Common After Simultaneous Pancreas Kidney Transplantation? A Single-Center Experience.

Post-transplant erythrocytosis (PTE) is reported in 8% to 22% of kidney transplant recipients. Few studies have evaluated the prevalence of PTE in simultaneous kidney-pancreas transplantation (SPKT). This study aimed to evaluate the prevalence of PTE in a cohort of SPKT and same-donor single kidney transplant patients and find predictive factors for erythrocytosis development. A single-center retrospective cohort study was performed with 65 SPKT recipients and 65 same-donor single kidney transplant patients. Post-transplant erythrocytosis was defined as a hematocrit persistently >51% without a known cause of erythrocytosis. The PTE prevalence was 23.1% and was more frequent in SPKT patients than in single donor patients (38.5% vs 7.7%; P < .001). The mean time for PTE development was 11.2 ± 13.3 months. In the multivariate model, SPKT was the only predictor for PTE development. De novo hypertension was more frequent in the PTE group (P = .002), but there was no difference in stroke and pancreatic or kidney thrombosis occurrence. Post-transplant erythrocytosis is more common after SPKT than after single kidney transplantation. De novo hypertension was more frequent in the erythrocytosis group, but allograft thrombosis rates.

Erythrocytosis and thrombotic events in kidney transplant recipients prescribed a sodium glucose cotransport-2 inhibitor.

INTRODUCTION: The safety and efficacy of sodium glucose cotransport-2 inhibitors (SGLT2i) in kidney transplant recipients remains uncertain. Transplant recipients may be at risk of thrombosis because of post-transplant erythrocytosis and SGLT2i are associated with an increase in hematocrit. METHODS: We determined SGLT2i use, the change in hematocrit and incidence of thrombotic events in kidney transplant recipients in 1700 prevalent patients in our center. RESULTS: Among the 42 patients treated with SGLT2i, the mean pre-transplant hematocrit was 31%, and none of the patients had a hematocrit ≥50%. The mean percent change in hematocrit measured at an average of 53 days after initiation of an SGLT2i was 11% and four patients (10%) had a hematocrit ≥ 50%. The mean hematocrit measured 3 months after treatment was 42% and two patients (5%) had a hematocrit ≥50%. One patient had a cerebellar stroke 14 months post-SGLT2i initiation when the hemoglobin was 173 grams/liter, and the hematocrit was 52%. CONCLUSIONS: All patients had a sustained increase in hematocrit 3 months after SGLT2i treatment. Hematocrit ≥50% occurred in 10%, and one patient had a thrombotic event that may or may not have been related to an increase in hematocrit. Clinicians may consider monitoring for erythrocytosis after starting and SGLT2i in kidney transplant recipients.

Hematometabolic Index as a New Discriminator of Cardiometabolic Risk in Middle-Aged Men with Polycythemia and High Leukocyte Count in Peripheral Blood.

Background: Both polycythemia and high leukocyte count are associated with the risk of cardiovascular disease. However, it remains to be determined whether polycythemia and high leukocyte count show synergistic increasing effects on cardiometabolic risk. Methods: Cardiometabolic risk was evaluated by cardiometabolic index (CMI) and metabolic syndrome in a cohort of middle-aged men (n = 11,140) who underwent annual health check-up examinations. The subjects were divided into three tertile groups by hemoglobin concentration or leukocyte count in peripheral blood, and their relations with CMI and metabolic syndrome were investigated. A new index, named hematometabolic index (HMI), was defined as the product of hemoglobin concentration (g/dL)-minus-13.0 and leukocyte count (/µL)-minus-3000. Results: When the subjects were further classified by tertiles for hemoglobin concentration and leukocyte count into nine groups, the odds ratios for high CMI and metabolic syndrome of the group categorized in the highest (third) tertiles for both hemoglobin concentration and leukocyte count versus the group of the lowest (first) tertiles for both of them were highest among the nine groups. In receiver-operating characteristic (ROC) analysis for relationships of HMI with high CMI and metabolic syndrome, areas under the ROC curves (AUCs) were significantly larger than the reference level and tended to be smaller with an increase in age. In subjects from 30 to 39 years of age, the AUC for the relationship between HMI and metabolic syndrome was 0.707 (0.663-0.751) and the cutoff of HMI was 9850. Conclusions: HMI, reflecting hemoglobin concentration and leukocyte count, is thought to be a possible marker for discriminating cardiometabolic risk.

Association between polycythemia and risk of ischemic stroke in males based on the national health insurance service-health screening cohort.

BACKGROUND: Polycythemia, a state in which the hematocrit or hemoglobin (Hb) concentration in the peripheral blood increases, is associated with several thrombosis-related diseases, of which cerebral infarction is relatively common. This study aimed to investigate the association between ischemic stroke and polycythemia, as a potential risk factor. RESEARCH DESIGN AND METHODS: This study included men who had undergone national health checkups between 2002 and 2003; the data were extracted from the Korean National Health Insurance Service-Health Screening database. The primary outcome was the risk ischemic stroke; adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for ischemic stroke were calculated using Cox proportional hazards regression models. RESULTS: In total, 207,737 male participants aged 40-79 years were included in this study. At the baseline, 13972 (6.7%) participants met the polycythemia criteria (Hb >16.5 g/dL). During the study period, 897 and 12,440 cases of ischemic stroke occurred in the polycythemia and normocythemia (13.0 g/dL ≤ Hb ≤16.5 g/dL) groups, respectively. Compared with the normocythemia group, the polycythemia group showed an adjusted HR (95% CI) for ischemic stroke of 1.12 (1.04-1.20). CONCLUSIONS: The risk of ischemic stroke was higher in participants with polycythemia than in those with normocythemia.

Polycythemia among Patients with Chronic Obstructive Pulmonary Disease Admitted to the Department of Medicine in a Tertiary Care Center: A Descriptive Cross-sectional Study.

Introduction: Chronic obstructive pulmonary disease is a preventable and treatable disease marked by persistent airflow limitation. Abnormal rise of haemoglobin and/or hematocrit in peripheral blood is known as polycythemia which includes increased haemoglobin: greater than 16.5 g/dl in men or greater than 16.0 g/dl in women and increased hematocrit: >49% for men and >48% for women. Men, current smoking, impaired carbon monoxide diffusing capacity, severe hypoxemia, and high altitude living are risk factors associated with an increased risk for secondary polycythemia. Polycythemia contributes to the development of cor-pulmonale and pulmonary hypertension, which are linked to poor prognosis. This study aimed to find out the prevalence of polycythemia among patients with chronic obstructive pulmonary disease admitted to the department of medicine in a tertiary care centre. Methods: A descriptive cross-sectional study was conducted among patients with chronic obstructive pulmonary disease admitted to the Department of Medicine in a tertiary care centre after receiving ethical approval from Institutional Review Committee (Reference number: 153/079/080). The study was conducted from 15 September 2022 to 2 December 2022. Data were collected from the hospital records. A convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated. Results: Among 185 patients, Polycythemia was seen in 8 (4.32%) (1.39-7.25, 95% Confidence Interval) patients among which 7 (87.5%) were females and 1 (12.5%) were male. Conclusions: The prevalence of polycythemia was lower compared to other similar studies done in similar settings. Keywords: chronic obstructive pulmonary disease; polycythemia; prevalence.

Prevalence and diagnostic performance of iron deficiency in polycythemia.

INTRODUCTION: Several observations have shown that patients with polycythemia have iron deficiency. Our objectives were to report the prevalence of iron deficiency and to evaluate the diagnostic performance of serum ferritin in polycythemia vera. PATIENTS AND METHOD: This is a retrospective descriptive and analytical study carried out in the internal medicine department of the Henri Mondor Hospital, Aurillac, France. The study involved 114 patients with polycythemia, followed in the department from January 1, 2010 to December 31, 2021. To evaluate the diagnostic performance, the JAK2 mutation was considered as the gold standard of diagnosis. RESULTS: Thirty-three patients had polycythemia vera and 76 patients had secondary polycythemia. The mean age of the patients was 61.79 years (±15.44) with a sex ratio of 4.43. The overall prevalence of iron deficiency was 21.05%. The prevalence was 53% in polycythemia vera group and 1.32% in secondary polycythemia group. The risk of iron deficiency was high in polycythemia vera (OR = 115; 95% CI [14.4-918.2], p < 0.0001) and the sensitivity and specificity of serum ferritin were 52.63% and 100% respectively. CONCLUSION: Assessment of iron deficiency should be part of the initial evaluation of polycythemia. Iron deficiency had a high specificity during polycythemia vera.

Prevalence of High-Altitude Polycythemia and Hyperuricemia and Risk Factors for Hyperuricemia in High-Altitude Immigrants.

Song Zhen, Anxin Zhang, Jie Luo, Guanghai Xiong, Haibo Peng, Rang Zhou, Yuanfeng Li, Hongqiang Xu, Zhen Li, Wei Zhao, and Haoxiang Zhang. Prevalence of high-altitude polycythemia and hyperuricemia and risk factors for hyperuricemia in high-altitude immigrants. High Alt Med Biol. 24:132-138, 2023. Background: Few studies have investigated the epidemiology of chronic mountain sickness (CMS) in high-altitude immigrants. This study evaluated the prevalence of polycythemia and hyperuricemia (HUA) and risk factors for HUA in high-altitude immigrants. Methods: A cross-sectional study was conducted with 7,070 immigrants 15-45 years of age living on the Tibetan Plateau between January and December 2021. Information from routine physical examinations was obtained from each participant. Binary logistic regression analysis was performed to determine the correlation of several risk factors for HUA. Results: The prevalence of high-altitude polycythemia (HAPC) and HUA was 25.8% (28.7% in males and 9.4% in females) and 54.2% (59.9% in males and 22.5% in females), respectively. The highest prevalence of HAPC in males and females was observed in participants 26-30 and 21-25 years of age, respectively. The highest prevalence of HUA in both males and females was observed in participants 26-30 years of age. Binary logistic regression analysis showed that age, sex, and hemoglobin (Hb) concentration were risk factors for HUA, among which age was a negative factor and male sex and Hb concentration were positive factors. Conclusions: Immigrants are more susceptible to HAPC and HUA. The high prevalence of CMS of immigrants may be associated with Hb concentration, age, and sex.

Erythrocytosis, thrombocytosis, and rate of recurrent thromboembolic event-A population based cohort study.

INTRODUCTION: The management to reduce risk of thromboembolic complications in polycythemia vera and essential thrombocythemia are well established, but for other conditions with elevated hemoglobin, hematocrit, or platelets there are no consensus regarding treatment and follow up. AIMS: To assess frequency of elevated blood values in patients with thromboembolic event, how many of these should be investigated further regarding myeloproliferative neoplasm and if the risk of recurrent event is depending on underlying condition. METHODS: Retrospective cohort study of 3931 adult patients in the county of Norrbotten, Sweden, with thromboembolism during 2017 and 2018. RESULTS: Of the 3931 patients, 1195 had either elevated Hb, HCT, or platelets fulfilling the 2016 revised WHO criteria for PV and ET, and out of these 411 should be evaluated regarding underlying myeloproliferative neoplasms. Unexplained thrombocytosis and secondary erythrocytosis were associated with the highest rate of recurrent event as well as the most inferior restricted mean survival time. CONCLUSION: Elevated blood values are common in patients with thromboembolic event and the high risk of recurrent event and inferior restricted mean survival time in patients with unexplained thrombocytosis and secondary erythrocytosis implicates the importance of finding and managing the underlying condition.

Twin Anemia-Polycythemia Sequence (TAPS): From Basic Research to Clinical Practice.

Twin pregnancy is associated with an increased risk of perinatal and maternal complications, and early establishment of the chorionicity type defines this risk. In monochorionic (MC) pregnancies, the fetuses share the same placental mass and exhibit vascular anastomoses crossing the intertwin membrane, and the combination and pattern of anastomoses determine the primary clinical picture and occurrence of future complications. Twin Anemia-Polycythemia Sequence (TAPS) was first described in 2006 after fetoscopic laser surgery in twin-to-twin transfusion syndrome (TTTS) twins, and in 2007, the first spontaneous cases were reported, recognizing TAPS as an individualized vascular identity in fetofetal transfusion syndromes. There are two types of TAPS: spontaneous (3-5%) and iatrogenic or postlaser (2-16%). TAPS consists of small diameter arteriovenous anastomoses (<1 mm) and low-rate, small-caliber AA anastomoses in the absence of amniotic fluid discordances. There are certain antenatal and postnatal diagnostic criteria, which have progressively evolved over time. New, additional secondary markers have been proposed, and their reliability is being studied. The best screening protocol for TAPS in MC twins is still a matter of debate. This review provides a survey of the relevant literature on the epidemiology, vascular pathophysiology, underlying hemodynamic factors that regulate mismatched vascular connections, and diagnostic criteria of this condition. The aim is to increase awareness and knowledge about this recently identified and frequently unrecognized and misdiagnosed pathology.

Comparing Rates of Polycythemia in Hypogonadal Men Using Nasal Testosterone Gel Versus Intramuscular Testosterone: Update of a Randomized Clinical Trial.

Men with hypogonadism who use intranasal testosterone are less likely to develop polycythemia than men using intramuscular testosterone cypionate.

Incidence, Contributing Factors, and Implications for Clinical Management of Polycythemia in Transmasculine Patients on Testosterone.

Purpose: The goal of this study was to evaluate contributing factors and management strategies for polycythemia in transmasculine patients on testosterone therapy. Methods: A retrospective analysis of medical records was performed for transmasculine patients on testosterone for at least 12 months. Data collected from each patient included age, body mass index (BMI), nicotine dependence, pulmonary disease status, obstructive sleep apnea (OSA) status, oophorectomy status, and testosterone route of administration. For patients who developed polycythemia, polycythemia management strategy data were collected. Results: Five-hundred-eleven patients were evaluated and 113 (22%) experienced an episode of polycythemia. Within the polycythemia group, 77% of patients were younger than age 40, 56% had a BMI >30.0, 44% had current or former nicotine dependence, 12% had a pulmonary disease, 12% had OSA, and 47% had received an oophorectomy. The polycythemia group had a significantly higher average age, BMI, and dose of testosterone, and also had a higher proportion of patients with OSA and an oophorectomy. Conclusion: These results revealed that polycythemia is a common side effect for transmasculine patients on testosterone. Importantly, previous oophorectomy may be associated with polycythemia which appears to be a novel finding. This finding requires further research but provides the potential to be an important screening consideration for transmasculine patients after oophorectomy. Polycythemia will continue to be a major concern for patients on testosterone therapy, and this study provided important information for clinical practice and future research that will lead to improved outcomes.

Secondary causes of elevated hemoglobin in patients undergoing molecular testing for suspected polycythemia vera in southwestern Ontario: a chart review.

BACKGROUND: Molecular testing for JAK2 mutations is part of the standard diagnostic workup for patients with suspected polycythemia vera. We sought to characterize evolving practice patterns in the investigation of erythrocytosis and the prevalence of secondary causes, including use of medications such as sodium-glucose cotransporter-2 (SGLT2) inhibitors, among patients who underwent molecular testing. METHODS: We reviewed charts of all consecutive patients investigated for erythrocytosis (hemoglobin > 160 g/L for women, > 165 g/L for men) with JAK2 testing between 2015 and 2021 at London Health Sciences Centre, a tertiary referral centre in Ontario, Canada, to assess changes in rates of JAK2 mutation positivity, average hemoglobin levels and the prevalence of secondary causes of erythrocytosis. RESULTS: A total of 891 patients with erythrocytosis underwent JAK2 mutation testing with an increase in number of tests (particularly from 2017 to 2018), a decrease in the rate of JAK2 positivity and similar average hemoglobin levels over the study period. We observed a high proportion of patients with secondary causes of erythrocytosis, ranging from 59% to 74% over the study period, including medications associated with erythrocytosis, namely testosterone (6%-11%) and SGLT2 inhibitors (2%-19%). Stopping SGLT2 inhibitors was associated with a significant decrease in hemoglobin levels (mean -14.7 g/L, 95% confidence interval -18.9 to -10.5 g/L) compared with continuation. INTERPRETATION: Use of SGLT2 inhibitors may be a common and underrecognized secondary cause of elevated hemoglobin levels in patients investigated for erythrocytosis. Our findings underscore the importance of a detailed medical history to support judicious use of molecular testing, in adherence with the current guideline on the investigation of erythrocytosis.

Prevalence of elevated hemoglobin and hematocrit levels in patients with obstructive sleep apnea and the impact of treatment with continuous positive airway pressure: a meta-analysis.

OBJECTIVES: Obstructive sleep apnea (OSA) is reported to be a cause of secondary polycythemia. The present study (i) reviewed the literature reporting the prevalence of secondary polycythemia in patients with OSA and (ii) determined the effect of continuous positive airway pressure (CPAP) therapy on hemoglobin and hematocrit levels in patients with OSA. METHODS: We searched MEDLINE, Embase and Cochrane for studies of adult patients with OSA that reported hemoglobin and/or hematocrit levels. We performed summary estimates of (i) polycythemia prevalence and a subgroup analysis according to OSA severity, and (ii) change in hemoglobin and hematocrit levels following treatment with CPAP. RESULTS: Synthesis of seven studies including 3,654 patients revealed an overall polycythemia prevalence of 2% (95% CI 1-4%); 2% (95% CI 1-3%) in mild-to moderate and 6 % (95% CI 3-12%) in severe OSA. In the pooled analysis of ten single-arm trials including 434 patients, CPAP treatment reduced hemoglobin by 3.76 g/L (95% CI -4.73 to -2.80 g/L). Similarly, pooled analysis of ten single-arm trials including 356 patients without baseline polycythemia showed that CPAP treatment reduced hematocrit by 1.1% (95% CI -1.4 to -0.9%). CONCLUSION: Our pooled analysis supports an increased prevalence of secondary polycythemia in OSA. This estimated prevalence is likely underestimated due to the change in the polycythemia diagnostic criteria in 2016. Future randomized controlled trials are needed to evaluate the effect of CPAP in patients with baseline polycythemia. HIGHLIGHTS: Pooled analysis shows OSA is associated with an increased prevalence of secondary polycythemiaPrevalence of polycythemia is greater in severe OSACPAP treatment for OSA reduces both the hemoglobin and hematocrit.

Cardiovascular benefits of SGLT2 inhibitors in type 2 diabetes, interaction with metformin and role of erythrocytosis: a self-controlled case series study.

BACKGROUND: Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have proven cardiovascular benefits in patients with type 2 diabetes (T2D). This self-controlled case series study aims to evaluate whether metformin use and SGLT2i-associated erythrocytosis influence its cardiovascular benefits. METHODS: T2D patients with metformin and/or SGLT2i prescriptions between 2015 and 2020 were identified from the Hong Kong population. Study outcomes were composite cardiovascular diseases (CVD), coronary heart disease (CHD), hospitalisation for heart failure (HHF), stroke, and erythrocytosis. Risk periods were patient-time divided into four mutually exclusive windows: (i) 'baseline period' of metformin use without SGLT2i; (ii) pre-SGLT2i period; (iii) exposure to SGLT2i without metformin; and (iv) exposure to the drug combination. Another SCCS model was applied to evaluate the association between erythrocytosis and cardiovascular outcomes regarding SGLT2i exposure. Four mutually exclusive risk periods included (i) SGLT2i exposure with erythrocytosis; (ii) SGLT2i exposure without erythrocytosis; (iii) absence of SGLT2i exposure with erythrocytosis; and (iv) absence of SGLT2i exposure without erythrocytosis. Incidence rate ratios (IRR) of events at different risk periods were estimated using conditional Poisson regression model. RESULTS: Among 20,861 patients with metformin and/or SGLT2i prescriptions, 2575 and 1700 patients with events of composite CVD and erythrocytosis were identified, respectively. Compared to metformin use without SGLT2i, SGLT2i initiation was associated with lower risks of composite CVD, CHD, and HHF-regardless of the presence (CVD: IRR = 0.43, 95% CI 0.37-0.51; CHD: IRR = 0.44, 95% CI 0.37-0.53; HHF: IRR = 0.29, 95% CI 0.22-0.40; all p < 0.001) and absence of concomitant metformin (CVD: IRR = 0.31, 95% CI 0.20-0.48; CHD: IRR = 0.38, 95% CI 0.25-0.59; HHF: IRR = 0.17, 95% CI 0.09-0.31; all p < 0.001); while SGLT2i was neutral on stroke risk. Compared to metformin-SGLT2i combination, exposure to SGLT2i alone was associated with comparable risks of all cardiovascular outcomes (all p > 0.05). Incidence rates of erythrocytosis at baseline, SGLT2i without and with metformin use periods were 0.75, 3.06 and 3.27 per 100 person-years, respectively. SGLT2i users who developed erythrocytosis had lower risk of HHF (IRR = 0.38, 95% CI 0.14-0.99, p = 0.049) than those who did not. CONCLUSIONS: Our real-world data suggested that SGLT2i-associated cardiovascular benefits were not attenuated by metformin use. Further studies will delineate the role of erythrocytosis as a surrogate marker of SGLT2i-associated cardiovascular benefit in reducing HHF.

Perinatal outcomes of pregnancies with twin-anemia polycythemia sequence complicating twin-to-twin transfusion syndrome using different twin-anemia polycythemia sequence diagnostic criteria.

OBJECTIVE: To investigate whether the presence of twin-anemia polycythemia sequence (TAPS) with twin-to-twin transfusion syndrome (TTTS) or post-laser TAPS would change outcomes using different TAPS diagnostic criteria. METHODS: TTTS cases undergoing laser surgery between 2012 and 2020 were included. Groups included pre-laser TTTS-only compared to TTTS + TAPS, and no post-laser TAPS compared to post-laser TAPS. Three prenatal TAPS diagnostic criteria were used: group A: middle cerebral artery-peak systolic velocity (MCA-PSV) > 1.5 MoM in one twin and <1 MoM in the other twin, group B: inter-twin MCA-PSV difference >1 MoM, and group C: inter-twin MCA-PSV difference >0.5 MoM. Perinatal outcomes including survival and severe cerebral injury were investigated. RESULTS: 174 laser procedures were included. TTTS + TAPS cases were 16 in group A, 17 in group B, and 29 in group C. Post-laser TAPS cases were 11 in group A, 6 in group B, and 12 in group C. There were no differences in preoperative, operative variables and outcomes including survival and severe cerebral injury between groups using all three TAPS diagnostic criteria. The incidence of TTTS + TAPS was highest in group C (16.7%), then group B (9.8%), followed by group A (9.2%). The incidence of post-laser TAPS was highest in group C (9%), then group A (8.3%), followed by group B (4.5%). CONCLUSION: Presence of TAPS complicating TTTS and presence of post-laser TAPS do not seem to be associated with worse perinatal outcomes including postnatal-ultrasound detected cerebral injury using three different TAPS criteria. Collaborative studies are needed to investigate the validity and the performance of different TAPS criteria.

High rates of neonatal polycythemia and hyperbilirubinemia during the first phase of COVID-19 pandemic in Italy: a single-center experience.

In our third-level Neonatal Unit in Northern Italy, we recorded a high rate of neonatal hyperbilirubinemia requiring phototherapy in March-November 2020, during the first phase of COVID-19 pandemic, compared to the previous year (198/1348, 14.2%, vs 141/1432, 9.8%, p = 0.0004). Supposing it could be the result of neonatal polycythemia, we evaluated capillary hematocrit (Hct) and the rate of hyperbilirubinemia in all newborns ≥36 weeks gestational age born in December 2020. Out of 73 neonates, 37 had Hct ≥65% (50.7%). However, as capillary blood samples may overestimate Hct by 5-15%, even downsizing all values by 15%, Hct was still ≥65% in 9/73 neonates (12.3%), much higher than 0.4-5% prevalence of polycythemia reported in healthy newborns. All those newborns were singleton and healthy, with no clinical signs of hyperviscosity and no underlying factors predisposing to polycythemia. Out of 73 newborns, 13 (17.8%) developed hyperbilirubinemia requiring phototherapy. Their mean Hct value was 66.3 ± 8.2%. Since hyperbilirubinemia is common in the offspring of women with SARS-CoV-2 infection and we recorded increased rates of neonatal hyperbilirubinemia in the first phase of COVID-19 pandemic, it could be hypothesized that even asymptomatic Sars-CoV2 infection during pregnancy might cause placental vascular malperfusion, eliciting polycythemia in the fetus as a compensatory response, that could be the link between COVID-19 in the mothers and hyperbilirubinemia in the newborns.