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Objectives Type 2 diabetes (T2DM) has been associated with several mental disorders including depression. Brain-derived neurotrophic factor (BDNF) has been suggested as a mediator between T2DM and depression. We investigated the association between BDNF and depression in T2DM patients in a primary health facility in Ghana.Methods In a case-control study design, depression was assessed using the Patient’s Health Questionnaire (PHQ-9) in 200 T2DM patients and 160 non-diabetic controls. A structured questionnaire was used to collect data on lifestyle, socio-demography and medical history. Fasting blood samples were collected from each participant to measure plasma lipid profile and serum BDNF levels.Results T2DM patients had higher levels of depression (31.5% vs 10.6, p

Background: Sickle cell disease (SCD) has evolved from a condition predominantly fatal in childhood to a chronic illness impacting many adults, including women of reproductive age. For females with SCD, pregnancy represents one of the greatest health threats, exacerbating existing health challenges and introducing new risks. Despite advancements in healthcare, routine screening for existing complications like pulmonary hypertension (PH) remains inconsistent, particularly in low- and middle-income countries (LMICs), where the prevalence of SCD is highest. Objective: This study aimed to assess the feasibility of screening for PH in pregnant women with SCD in LMICs, with the goal of enhancing maternal health outcomes in this vulnerable population. Study Design: A prospective multi-center feasibility study was conducted from September 2022 to February 2023 at teaching hospitals in Ghana and Nigeria. The study included pregnant women with SCD between 28 and 34 weeks of gestation. Screening for PH utilized a tricuspid regurgitation velocity (TRV) criterion (>2.5 m/s), with adherence to American Society of Echocardiography guidelines. Statistical analysis included descriptive statistics and proportions. Results: Among 3091 pregnant women attending antenatal care, 88 had SCD (2.8%), and 55 were eligible for the study. We recruited 44 participants (mean age 28.9 years, SD 4.8), with 48% (21/44) SS genotype and 52% (23/44) SC genotype. Most participants (95.3%) had normal TRV (

Background: Type 2 diabetes (T2DM) is associated with high burden of atherosclerotic macrovascular disease which could be diagnosed with ankle-brachial index (ABI). Phase angle (PhA) from bioelectric impedance analysis is associated with the development of cardiovascular diseases. We investigated the association between low ABI and phase angle in T2DM patients in Ghana. Method: In a cross-sectional study, 462 T2DM patients were systematically recruited for the study. ABI was measured using an 8 Hz continuous Doppler and ABI≤0.9 was considered to be low ABI. PhA was obtained from resistance and reactance from Bioelectric impedance analysis. Results: The prevalence of low ABI was 16 % in the study population. T2DM patients with low ABI have decreased PhA (7.5 ± 1.9 vs 8.3 ± 2.2 units, p = 0.004) compared to those with normal ABI. An increase in phase angle by 1° was associated with a decrease in odds of having low ABI in unadjusted [OR (95 % CI) = 0.79 (0.48 – 0.95), p = 0.007] and adjusted models [0.88 (0.43 – 0.98), p = 0.036]. Conclusion: The prevalence of low ABI in T2DM patients in this study was 16 %. Also, PhA was lower in patients with low ABI compared to those with normal ABI.

Abstract Background Brain-derived neurotrophic factor (BDNF) has been implicated in the development of cardiometabolic risk factors in some populations. However, few studies have investigated the role of BDNF and cardiometabolic risk factors in HIV patients despite the plethora of evidence linking HIV infection with the dysregulation of circulating BDNF levels. We investigated the association between serum BDNF and cardiometabolic risk factors in HIV patients in a primary hospital in Ghana. We recruited 450 participants, comprising 150 combination antiretroviral (cART)-treated HIV patients, 150 cART-naïve HIV patients, and 150 non-HIV controls. Data on sociodemographic parameters and medical history were collected using a structured questionnaire. Fasting venous blood samples were collected to measure plasma glucose levels, lipid profiles, and BDNF. Metabolic syndrome (MetS) was defined using the joint interim statement criteria. Results Compared to untreated HIV patients and uninfected controls, the proportion of participants having MetS was high in cART-exposed HIV patients (26.8% vs 21.1% vs 52.1%, respectively, p

BackgroundAlthough AIDS-related deaths have reduced with increased access to antiretroviral care, cardiovascular disease-related morbidities among persons living with HIV are rising. Contributing to this is the higher incidence of Hypertension among Persons Living with HIV. The duration of exposure to the virus and antiretroviral drugs plays a vital role in the pathogenesis, putting perinatally infected children and adolescents at higher risk than behaviorally-infected ones, supporting the calls for increased surveillance of Hypertension among them. Despite the availability of guidelines to support this surveillance, the blood pressure (BP) of adolescents living with HIV (ADLHIV) is not checked during clinical visits. This study aims to assess the effect of a theory-based intervention on healthcare workers' adherence to the guidelines for hypertension screening among adolescents.MethodsA multi-facility cluster-randomized study will be conducted. The clusters will be 20 antiretroviral therapy sites in the Greater Accra Region of Ghana with the highest adolescent caseload. Data will be extracted from the folders of adolescents (10-17 years) who received care in these facilities six months before the study. The ART staff of intervention facilities will receive a multicomponent theory of planned behaviour-based intervention. This will include orientation on hypertension risk among ADLHIV, provision of job aids and pediatric sphygmomanometers. Six months after the intervention, the outcome measure will be the change from baseline in the proportion of ADLHIV whose BP was checked during clinical visits. The calculated sample size is 400 folders.Implications of findingsThis study will generate evidence on the effectiveness of a multicomponent theory-based intervention for improving the implementation of clinical practice guidelines.Trial registrationPACTR202205641023383.

ABSTRACTHuman immunodeficiency virus (HIV) infection is associated with increased cardiovascular diseases (CVDs) even in patients with viral suppression by combination antiretroviral therapy (cART). Arterial stiffness is an independent predictor of CVDs in diseased individuals and the general population. Cardio-ankle vascular index (CAVI) is an index of arterial stiffness that has been shown to predict target organ damage. CAVI is less studied in HIV patients. We compared the levels of arterial stiffness using CAVI and associated factors among cART-treated and cART-naïve HIV patients to those of non-HIV controls. In a case-control design, 158 cART-treated HIV patients, 150 cART-naïve HIV patients and 156 non-HIV controls were recruited from a periurban hospital. We collected data on CVD risk factors, anthropometric characteristics, CAVI, and fasting blood samples to measure plasma glucose, lipid profile, and CD4+ cell counts. Metabolic abnormalities were defined using the JIS criteria. CAVI increased in cART-treated HIV patients compared to cART-naïve HIV patients and non-HIV controls (7.8 ± 1.4 vs 6.6 ± 1.1 vs 6.7 ± 1.4 respectively, p

Objective: Peripheral sensory neuropathy (PSN) is a common complication of type 2 diabetes (T2DM) that can lead to frequent ulcerations, lower extremities, and reduced quality of life. Imbalance in the circulating levels of angiogenic growth factors, notably, angiopoietin (Ang)-1, Ang-2 and vascular endothelial growth factor (VEGF) may be among the underlying mechanisms of PSN in T2DM patients. We studied the association between PSN and angiogenic growth factors, Ang-1, Ang-2 and VEGF in T2DM patients in Ghana. Methods: In a case-control study design, PSN was evaluated in 160 patients with T2DM and 108 nondiabetic controls using vibration perception threshold (VPT) and diabetic neurological examination (DNE). The definition of PSN was abnormal VPT (≥25 mV) or the presence of neuropathic symptoms on examination (DNE score > 3). In addition, fasting venous blood samples were collected to measure circulating levels of Ang-1, Ang-2 and VEGF. Results: Compared to non-diabetic controls, patients with T2DM had a higher prevalence of PSN using abnormal VPT (20.6 % vs 2.8 %, p

Abstract Background Diabetes patients are at risk of developing mental health comorbidities such as depression and poor quality of sleep. These conditions can affect diabetic management, including glycemic and plasma lipid control to optimal levels. We investigated the association between diabetic control and the presence of depression and poor sleep quality in type 2 diabetes (T2DM) patients at Sunyani Government hospital in Ghana. Using a case–control design, we recruited 200 T2DM patients and compared them to 160 non-diabetic controls. The presence of depression was assessed using the Patient Health Questionnaire (PHQ)-9 and sleep quality using the Pittsburgh Sleep Quality Instrument (PSQI). Blood samples were collected to measure glycated hemoglobin (HbA1c) levels and plasma lipid profiles. Poor glycemic control was defined as HbA1c > 7%, depression as PHQ-9 score > 9 and poor sleep quality as PSQI score ≥ 5. Results T2DM patients had a higher prevalence of depression (31.5% vs 10.6%, p

Abstract Background T cell receptors play important roles in the development and progression of rheumatoid arthritis (RA). Their involvement has been reported in inflammatory autoimmune diseases. However, their role in predicting RA is still under exploration. This study evaluated the expression of CD183 (CXCR3) receptors on T‐cells and other relevant biomarkers for detecting RA and determine their relationship with disease activity. Methods This unmatched case–control study included 48 newly diagnosed RA patients and 30 apparent healthy controls from the orthopedic units of Komfo Anokye Teaching Hospital (KATH), Kumasi and Korle‐Bu Teaching Hospital (KBTH), Accra, Ghana. Sociodemographic data was obtained, and blood samples were also collected and processed for flow cytometric analysis. Statistical analyses were done using SPSS version 26.0 and R programming language. p

Objective. Impaired angiogenesis, measured as serum levels of angiogenic growth factors, may be among the mechanisms underlining aortic stiffness in diabetes patients. We studied the association between aortic stiffness and circulating angiogenic growth factors in type 2 diabetes (T2DM) patients without any organ damage. Methods. In a case-control design, aortic pulse wave velocity (PWV), augmentation index (AIx), and aortic blood pressures (BPs) were measured in 140 T2DM patients and 110 nondiabetic controls. Fasting blood samples were collected to measure the levels of angiopoietin- (Ang-) 1, Ang-2, and vascular endothelial growth factor-A (VEGF). Results. Compared to nondiabetes participants, T2DM patients had increased PWV (8.7±1.5 vs. 7.6±1.3, p=0.031), aortic pulse BP (58±20 vs. 49±17, p=0.011), Ang-2 (838 (473–1241) vs. 597 (274–1005), p=0.018), and VEGF (72.2 (28–201.8) vs. 48.4 (17.4–110.1), p=0.025) but reduced levels of AIx (21.7±13.8 vs. 34±12.9, p

Background. There is an increasing prevalence of cardiovascular diseases (CVDs) and risk factors in HIV patients as the levels of AIDS-related mortality and morbidity decrease. Metabolic syndrome (MetS) is the accumulation of various CVD risk factors that predict the occurrence of CVDs. We investigated the prevalence of MetS and associated risk factors in HIV patients treated with combination antiretroviral therapy (cART), cART-naïve HIV patients, and non-HIV controls. Methods. In a case-control design, 158 cART-treated HIV patients, 150 cART-naïve HIV patients, and 156 non-HIV controls were recruited from a periurban hospital in Ghana. A structured questionnaire was used to collect data on demography, lifestyle, and medication. Anthropometric indices and blood pressure were measured. Fasting blood samples were collected to measure the plasma levels of glucose, lipid profile, and CD4+ cells. The presence of MetS was defined using the joint scientific statement criteria. Results. The prevalence of MetS was higher in cART-treated HIV patients compared with cART-naïve HIV patients and non-HIV controls (57.3% vs. 23.6% vs. 19.2% and p

Summary: Background: We undertook a Grand Challenges in Global Eye Health prioritisation exercise to identify the key issues that must be addressed to improve eye health in the context of an ageing population, to eliminate persistent inequities in health-care access, and to mitigate widespread resource limitations. Methods: Drawing on methods used in previous Grand Challenges studies, we used a multi-step recruitment strategy to assemble a diverse panel of individuals from a range of disciplines relevant to global eye health from all regions globally to participate in a three-round, online, Delphi-like, prioritisation process to nominate and rank challenges in global eye health. Through this process, we developed both global and regional priority lists. Findings: Between Sept 1 and Dec 12, 2019, 470 individuals complete round 1 of the process, of whom 336 completed all three rounds (round 2 between Feb 26 and March 18, 2020, and round 3 between April 2 and April 25, 2020) 156 (46%) of 336 were women, 180 (54%) were men. The proportion of participants who worked in each region ranged from 104 (31%) in sub-Saharan Africa to 21 (6%) in central Europe, eastern Europe, and in central Asia. Of 85 unique challenges identified after round 1, 16 challenges were prioritised at the global level; six focused on detection and treatment of conditions (cataract, refractive error, glaucoma, diabetic retinopathy, services for children and screening for early detection), two focused on addressing shortages in human resource capacity, five on other health service and policy factors (including strengthening policies, integration, health information systems, and budget allocation), and three on improving access to care and promoting equity. Interpretation: This list of Grand Challenges serves as a starting point for immediate action by funders to guide investment in research and innovation in eye health. It challenges researchers, clinicians, and policy makers to build collaborations to address specific challenges. Funding: The Queen Elizabeth Diamond Jubilee Trust, Moorfields Eye Charity, National Institute for Health Research Moorfields Biomedical Research Centre, Wellcome Trust, Sightsavers, The Fred Hollows Foundation, The Seva Foundation, British Council for the Prevention of Blindness, and Christian Blind Mission. Translations: For the French, Spanish, Chinese, Portuguese, Arabic and Persian translations of the abstract see Supplementary Materials section.

Abstract Background Diabetes and depression are both chronic debilitating conditions, and their coexistence has been associated with adverse outcomes. In this study, we investigated the association between glycaemic control and depression in type 2 diabetes (T2DM) patients attending a tertiary healthcare facility in Ghana. Methodology In a cross-sectional study design, Patient Health Questionnare-9 (PHQ-9) was used to assess depression in 400 T2DM, aged 30–65 years. Anthropometric characteristics and blood pressure were measured. Venous blood was collected to measure the levels of glycated haemoglobin (HbA1c). Results The prevalence of depression was 31.3% among T2DM patients. Female gender, being unmarried, frequent intake of alcohol, previous smoking status and insulin use were associated with increased odds of depression, whereas being educated above basic school level was associated with a decreased odds of depression. In a multivariable logistic regression model, being unmarried and poor glycaemic control were associated with an increase in odds of depression after adjusting for age, gender, and social factors. The association between depression and glycaemic control was attenuated when clinical factors were introduced into the model. Conclusion In our study population, we found that depression is common among Ghanaians with T2DM, and not associated with poor glycaemic control in a fully multivariable-adjusted model.

Abstract Background Metabolic syndrome (MetS) in young adults poses significant cardiovascular diseases (CVD) risk for later years. Parental history of CVDs is known to affect the prevalence of CVD risk in adulthood. In sub-Saharan Africa, the burden of MetS in young adults and its relationship with parental CVDs is largely unknown. We studied the gender-specific prevalence of MetS and its association with parental history of diabetes, hypertension and CVDs in young adults resident in urban Ghana. Methods In a cross-sectional design, 364 young adults aged 20–30 years were randomly recruited from students of University of Ghana. A structured questionnaire was used to collect data on demography, lifestyle, medical and parental medical history. Anthropometric indices and blood pressures were measured. Fasting blood samples were collected to measure plasma levels of glucose, lipid profile, urea and creatinine. MetS was defined according to the Joint Scientific Statement criteria. Results The prevalence of MetS was 12.4%, higher in females than male participants (18.4% vs 5.7, p = 0.019). Female participants had higher levels of all the components of MetS than the male participants. Compared to participants with no history of parental CVDs, participants with parental CVDs had a higher proportion of abdominal obesity. A positive history of parental CVDs was associated with increase in odds of MetS [OR (95% CI): 1.23 (1.12–3.04), p = 0.037]. Conclusion In our study population, there is relatively high prevalence of MetS; higher in females compared to male participants. Parental history of CVDs was associated with MetS.

Aim: Patients with HIV have increased cardiovascular risk and pulmonary defects. We investigated the association between impaired pulmonary function (IPF) and arterial stiffening measured by the cardio-ankle vascular index (CAVI) in Ghanaian HIV patients. Method: Spirometry was used to measure pulmonary indices; forced expiratory volume in 1s (FEV1) and forced vital capacity (FVC) in 79 HIV patients on treatment, 75 HIV treatment naïve patients and 78 non-HIV controls. We also used FEV1/FVC < lower limit of normal as a further index. Arterial stiffness was measured as CAVI using the Vasera device. Results: Compared to non-HIV controls, CAVI was higher in treatment naïve (6.9 ± 1.4 vs 6.3 ± 1.1 units, p < 0.01) and HIV patients on treatment (8.1 ± 1.4, vs 6.3 ± 1.1, p < 0.01). IPF was detected in 12 (15.2%) HIV patients on treatment, 8 (10.7%) treatment naïve HIV patients and 5 (6.4%) non-HIV controls. Compared to those without IPF, IPF patients had higher CAVI in non-HIV controls (6.5 ± 1.1 vs 5.7 ± 0.8, p < 0.01), treatment naïve HIV patients (7.1 ± 1.8 vs 6.6 ± 1.4, p = 0.023) and HIV patients on treatment (7.8 ± 1.4 vs 8.7 ± 1.2, p < 0.01). In multivariable logistic regression analysis, IPF was independently associated with CAVI [adjusted OR = 1.33 (1.15 – 1.89), p = 0.037] after adjustment for age [1.21 (0.98 – 2.14), p = 0.11], male sex [0.42 (0.32 – 0.91), p = 0.035], current/former smoking status [1.43 (0.47 – 4.01), p = 0.75] and history of tuberculosis infection [1.96 (1.08 – 3.12), p < 0.01]. Conclusion: Ghanaian HIV patients have a high prevalence of impaired respiratory function and arterial stiffening, and these indices are associated with each other.

Objective: Peripheral sensory neuropathy (PSN) is a common cause of ulceration and amputation in diabetes (DM) patients. The prevalence of PSN in DM patients is largely undetermined in sub-Saharan African population. We studied the burden of PSN in DM patients using a validated questionnaire and quantitative sensory test. Methods: In a case-control design, PSN was measured in 491 DM patients and 330 non-DM controls using Michigan neuropathy screening instrument (MNSI) and vibration perception threshold (VPT). PSN was defined as MNSI symptom score ≥7, MNSI examination score ≥2 or VPT ≥25V. Results: The prevalence of PSN screened by MNSI symptom score, MNSI examination score and VPT was 7.1%, 51.5% and 24.5% in DM patients; and 1.5%, 24.5% and 8.5% in non-DM participants respectively. The major determinants of PSN screened by MNSI examination score were diabetes status [OR (95% CI): 4.31 (2.94–6.31), p

Lupus nephritis (LN) is a complication of systematic lupus erythematosus (SLE) with significant impact on morbidity and mortality. It is known commonly to affect females but has worse prognosis when males or blacks are affected. In a setting with deficiency in health care delivery, the diagnosis and adequate management of SLE patients becomes difficult and hence less cases of lupus nephritis in black males have been reported. We present a case of a male black patient with SLE who presented with neurolupus, serositis, skin manifestations and Class IV/V lupus nephritis on histology. Our case highlights the challenges in the management of lupus nephritis and the complications with immunosuppression in an attempt to induce remission. There is the need for high index of suspicion for the diagnosis of lupus nephritis especially in black males for prompt management to get the best outcome.

Objective. Peripheral sensory neuropathy (PSN) is among microvascular complications of diabetes that make patients prone to ulceration and amputation. Arterial stiffness is a predictor of cardiovascular diseases and microvascular complications associated with diabetes. We investigated the association between PSN and arterial stiffness, measured as aortic pulse wave velocity (PWVao) and cardio-ankle vascular index (CAVI). Method. In a case-control design, arterial stiffness was measured in 240 diabetes patients and 110 nondiabetic control. Large-fibre nerve function was assessed by vibration perception threshold (VPT) using a neurothesiometer. PSN was defined as the VPT > 97.5th percentile from age- and gender-adjusted models in nondiabetic controls. Results. The overall prevalence of PSN was 16.6% in the entire study participants. Compared to non-PSN participants, PSN patients had higher levels of PWVao (9.5 ± 1.7 versus 8.7 ± 1.2 m/s, p=0.016) and CAVI (8.4 ± 1.3 versus 7.6 ± 1.1, p=0.001). In multiple regression models, VPT was associated with PWVao (β=0.14, p=0.025) and CAVI (β=0.12, p=0.04). PSN patients had increased odds of CAVI (OR = 1.51 (1.02–2.4), p=0.043), but not PWVao (OR = 1.25 (0.91–1.71), p=0.173). Conclusion. PWVao and CAVI were associated with VPT and PSN in diabetes patients in Ghana. Patients having PSN have increased odds of CAVI, independent of other conventional risk factors.

Objective: Systemic lupus erythematosus (SLE) is a chronic inflammatory disease associated with vascular derangement [1]. Leptin and adiponectin are adipokines with immunomodulatory and vascular functions [2]. We studied the association between arterial stiffness and plasma leptin and adiponectin levels in SLE patients in Ghana. Methods: In a case control design involving 80 SLE patients and 90 non-SLE controls, arterial stiffness was assessed by cardio-ankle vascular index (CAVI) and heart-ankle pulse wave velocity (haPWV) using Vasera 1500N. Circulating levels of leptin, adiponectin, insulin and C-reactive protein (CRP) were measured by ELISA. Results: Compared to non-SLE controls, SLE patients had higher levels of CAVI (7.3±1.1 vs 6.1±1, p < 0.001), haPWV (7.7±1.3 vs 6.5±0.8 m/s, p =

Objective. Peripheral arterial disease (PAD) is a common complication of diabetes, associated with impairment in angiogenesis. Angiogenesis is regulated by angiogenic growth factors such as angiopoietin 1 (Ang-1), Ang-2, and vascular endothelial growth factor (VEGF). We studied the association between angiogenic growth factors versus PAD and exertional leg symptoms in diabetes patients in Ghana. Method. In this cross-sectional study, ankle-brachial index was measured with oscillometrically and exertional leg symptoms were screened with Edinburgh claudication questionnaire in 140 diabetes patients and 110 nondiabetes individuals. Circulating levels of Ang-1, Ang-2, and VEGF were measured with immunosorbent assay. Results. The prevalence of PAD and exertional leg pain was 16.8% and 24.8%, respectively. Compared to non-PAD participants, PAD patients had higher VEGF levels [85.8 (37.5–154.5) versus 57.7 (16.6–161.1) p=0.032] and lower Ang-1 levels [31.3 (24.8–42.6) versus 40.9 (28.2–62.1), p=0.017]. In multivariable logistic regression, patients with exertional leg pain had increased the odds of plasma Ang-2 levels [OR (95% CI): 2.08 (1.08–6.41), p=0.036]. Conclusion. Diabetes patients with PAD and exertional leg pain have imbalance in angiogenic growth factors, indicating impaired angiogenesis. In patients with exertional leg pains, Ang-2 may be an important biomarker.

Background: Impaired angiogenesis may be amongst the possible mechanism underlining the development of peripheral sensory neuropathy (PSN) in type 2 diabetes (T2DM) patients.(1) Angiogenesis is regulated by circulating vascular growth factor, notably, angiopoietin (Ang)-1, Ang-2 and vascular endothelial growth factor (VEGF).(2) We studied the relationship between PSN and circulating vascular growth factors, Ang-1, Ang-2 and VEGF in T2DM patients. Method: PNS was assessed by vibration perception threshold (VPT) using Horwell’s neurothesiometer, and serum levels of Ang-1, Ang-2 and VEGF were also measured by Elisa in 107 T2DM patients and 93 nondiabetes subjects (controls). PNS was defined as VPT>25V. Results: The overall prevalence of PNS was 11.2% higher in T2DM patients (10.1% vs. 1.1%, p=0.012) than controls. T2DM patients had higher mean VPT (12.1±7.8 vs. 7.3±3.8 V, p

Background. Increased arterial stiffness is an independent cardiovascular risk factor in diabetes patients and general population. However, the contribution of diabetes to arterial stiffness is often masked by coexistent obesity and hypertension. In this study, we assessed arterial stiffness in nonhypertensive, nonobese type 2 diabetes (T2DM) patients in Ghana. Methods. In case-control design, 166 nonhypertensive, nonobese participants, comprising 96 T2DM patients and 70 nondiabetes controls, were recruited. Peripheral and central blood pressure (BP) indices were measured, and arterial stiffness was assessed as aortic pulse wave velocity (PWVao), augmentation index (AIx), cardioankle vascular index (CAVI), and heart-ankle pulse wave velocity (haPWV). Results. With similar peripheral and central BP indices, T2DM patients had higher PWVao (8.3 ± 1 versus 7.8 ± 1.3, p=0.044) and CAVI (7.9 ± 1.2 versus 6.9 ± 0.7, p=0.021) than nondiabetic control. AIx and haPWV were similar between T2DM and nondiabetic controls. Multiple regression models showed that, in the entire study participants, the major determinants of PWVao were diabetes status, age, gender, systolic BP, and previous smoking status (β = 0.22, 0.36, 0.48, 0.21, and 0.25, resp.; all p

The control of nitrous oxide (N2O) emissions through nitrification and the optimization of maize yield are important in agricultural systems. However, within the semi-arid region, the impact of fertilization on the function of nitrification communities and its connection with N2O emissions in the rhizosphere soil is still unclear. Our study investigates the influence of fertilization treatments on the communities of ammonia-oxidizing bacteria (AOB) and the complete ammonia oxidizers of the Nitrospira known as comammox (CAOB) in a maize agroecosystem. Nitrous oxide production, potential nitrification activity (PNA), maize yield, and nitrogen use efficiency (NUE) were determined for the same samples. The fertilizer treatments included a control group without fertilization (NA), inorganic fertilizer (CF), organic fertilizer (SM), combined inorganic and organic fertilizer (SC), and maize straw (MS). The SC treatment indicated a lower cumulative N2O emission than the CF treatment in the 2020 and 2021 cropping seasons. The AOB community under the CF, MS, and SM treatments was predominantly composed of Nitrosospira cluster 3b, while the SC treatment was associated with the comammox Nitrospira clade A.1 lineage, related to key species such as Ca. Nitrospira inopinata and Ca. Nitrospira nitrificans. Network analysis demonstrated a positive potential for competitive interaction between hub taxonomy and distinct keystone taxa among AOB and comammox Nitrospira nitrifiers. The structural equation model further revealed a significant positive association between AOB nitrifiers and N2O emission, PNA, soil pH, SOC, NO3--N, and DON under organic fertilization. The keystone taxa in the comammox Nitrospira nitrifier and network Module II exhibited a positive correlation with maize productivity and NUE, likely due to their functional activities stimulated by the SC treatment. It is noteworthy that the AOB community played a more significant role in driving nitrification compared to the composition of comammox Nitrospira. Collectively, combined inorganic and organic fertilizer (SC) treatment exhibits high potential for reducing N2O emissions, enhancingmaize productivity, increasingNUE, and increasing the sustainability of the nitrogen dynamics ofmaize agroecosystems in the semi-arid Loess Plateau. [ABSTRACT FROM AUTHOR]