Association of thyroid hormones with resting energy expenditure and complement C3 in normal weight high body fat women

Thyroid hormones in systemic lupus erythematosus: The catalyst for disease progression?

OBJECTIVE

The study aimed to investigate the impact of varying thyroid function statuses on clinical and laboratory indicators in patients with systemic lupus erythematosus (SLE).

METHODS

A retrospective analysis was conducted on 258 patients with SLE, who were stratified according to thyroid function, renal involvement, and disease activity. The predictive value of thyroid hormones was evaluated using a receiver operating characteristic (ROC) curve.

RESULTS

Among the 258 patients with SLE, 141 were classified as the normal group, while 117 exhibited thyroid hormone abnormalities, categorized into hypothyroidism (N=112) and hyperthyroidism (N=5) groups. Serum levels of FT3 and FT4 positively correlate with total protein and albumin, while negatively correlating with the SLE Disease Activity Index 2K (SLEDAI-2K) and 24-hour urinary protein (24hUP) (P<0.05). Compared to individuals without renal involvement, those with renal involvement exhibited lower levels of FT3 and FT4 (3.35±0.99 vs. 4.07±2.22, 12.92±3.14 vs. 14.63±3.39, P=0.001), along with elevated thyroid-stimulating hormone (TSH) levels (7.08±14.40 vs. 5.28±12.48, P=0.343). The subgroups in euthyroid (n=86) and hypothyroid (n=93) of SLE patients with renal involvement exhibited different characteristics (P<0.05). The levels of FT3 gradually decreased with increase of disease activity. The areas under the ROC curve of FT3, FT4, TSH and their combination were 0.651, 0.654, 0.643, 0.669, respectively (P<0.05).

CONCLUSIONS

The correlation between thyroid function and the severity of SLE is significant, SLE patients with hypothyroidism exhibit more pronounced disease manifestations and an elevated risk of organ damage. SLE patients with low levels of FT3 and FT4 are prone to progressing to nephritis.

The relationship between serum CTRP-5, C3a/desArg, and complement-C3 levels and hypothyroidism in women with polycystic ovary syndrome

INTRODUCTION

Many patients with polycystic ovary syndrome (PCOS) also experience thyroid disorders. There is a notable similarity in energy metabolism among PCOS, C1q/tumor necrosis factor (TNF)-related proteins (CTRP-5)deficiency, C3a/desArg (also known as acylation-stimulating protein (ASP)) deficiency, and hypothyroidism. This study aimed to investigate the relationship between serum levels of these factors and hypothyroidism in patients with PCOS. Improved clarity and vocabulary, corrected minor grammatical issues, and enhanced readability.

METHODS

This case-control study involved three groups: healthy women (control group), women with PCOS and hypothyroidism, and women with PCOS without hypothyroidism. Serum levels of FBS, total cholesterol, triglycerides, and HDL-C were measured using enzymatic and colorimetric methods. TSH, T4, T3, and anti-thyroid peroxidase (Anti-TPO) levels were determined by ELISA to screen for hypothyroidism in women with PCOS. Additionally, serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), CTRP-5, ASP, and complement C3 were assessed using the ELISA method.

RESULTS

The results indicated that reduced blood levels of CTRP-5, along with elevated levels of ASP (C3a/desArg) and complement C3 in patients with PCOS, may be linked to dysregulation of the thyroid gland. Furthermore, the study observed that changes in these parameters, in conjunction with thyroid dysfunction, are associated with pathological alterations in lipid profiles and blood glucose levels.

CONCLUSION

While changes in CTRP-5, ASP, and complement C3 can influence energy expenditure and storage in PCOS and thyroid function, the complex nature of PCOS requires further research to investigate the prevalence of hypothyroidism in individuals with PCOS.

CLINICAL TRIAL NUMBER

Not applicable.

Complement component C3 is associated with body composition parameters and sarcopenia in community-dwelling older adults: a cross-sectional study in Japan

BACKGROUND

Chronic inflammation is a factor in the pathogenesis of sarcopenia, which is characterized by low muscle mass and reduced strength. Complement C3 is important in the management of the immune network system. This study seeks to determine the relationship between serum C3 levels and body composition and sarcopenia-related status in community-dwelling older adults.

METHODS

Study participants were 269 older adults living in rural Japan. A bioelectrical impedance analysis device was used to measure body composition parameters including body mass index (BMI), body fat percentage, waist-hip-ratio, and appendicular skeletal muscle mass index (SMI). Muscle function was measured by handgrip strength and 6-m walking speed. The correlation coefficients for C3 level and measurements were calculated using Pearson correlation analysis. Participants were categorized into normal, pre-sarcopenia, dynapenia, or sarcopenia groups. Sarcopenia was defined according to 2019 Asian Working Group for Sarcopenia definition, dynapenia was defined as low muscle function without low muscle mass, and pre-sarcopenia was defined as the presence of low muscle mass only. The C3 threshold score for sarcopenia status was evaluated by receiver operating characteristic curve (ROC) analysis.

RESULTS

Significant positive correlations were found between C3 and BMI, body fat percentage, and waist-hip ratio in both sexes, and further positive correlations with SMI were found in women. The relationship with body fat percentage was particularly strong. Body composition measurements (BMI, body fat percentage, and waist- hip ratio) and C3 levels were lowest in the sarcopenia group compared with the others. ROC analysis showed that the significant threshold of C3 for discriminating between the normal and sarcopenia groups was 105 mg/dL. Multiple logistic regression analysis showed that participants with C3 < 105 mg/dL had an odds ratio of 3.27 (95% confidence interval, 1.49-7.18) for sarcopenia adjusted by sex, age and body fat percentage.

CONCLUSION

C3 levels are suggested to be related to body composition and pathophysiological functions of sarcopenia. C3 is expected to become a useful biomarker for sarcopenia, for predicting the onset of the disease and for predicting the effectiveness of interventions.

Association of normal weight obesity phenotype with inflammatory markers: A systematic review and meta-analysis

Background

Individuals with normal weight could suffer from obesity based on their body fat percentage (also known as normal weight obesity (NWO)), thus being at risk of significant morbidity and mortality compared to the general population. It seems that inflammatory pathways and chronic inflammation are significant contributors to the pathogenicity of NWO. This study aimed to assess and pool the association of proinflammatory and anti-inflammatory cytokines with NWO.

Methods

In this systematic review and meta-analysis, online international databases (PubMed, Scopus, EMBASE, Web of Science, and Google Scholar) were searched until August 2022. All observational studies with an English full text comparing the mean levels of proinflammatory and anti-inflammatory cytokines (e.g., C-reactive protein (CRP), various types of interleukins (IL) s, tumor necrosis factor-alpha (TNF)) and white blood cell (WBC) count, in subjects with NWO and "normal weight non-obese (NWNO)" were included. Two researchers independently screened, reviewed and assessed the quality of included studies. The remaining articles' data were extracted post-screening. The heterogeneity between studies was assessed using the I² and Cochran's Q tests. A random effect model meta-analysis was used to pool the standardized mean difference (SMD) as an effect size.

Results

From the initial 559 studies, 21 and 19 were included in the qualitative and quantitative synthesis, respectively. In the systematic review, 8 studies reported a significant association between various proinflammatory cytokines (CRP, IL₆, IL_1β, and TNFα) and NWO. According to random-effect meta-analysis, the association between NWO with CRP (SMD: 0.60, 95% CI: 0.30, 0.91) and IL6 (SMD: 0.90, 95%CI: 0.14, 1.66) was statistically significant. Moreover, the mean level of TNF_α in subjects with NWO and NWNO did not differ significantly (SMD: 0.67, 95% CI: -0.36, 1.70).

Conclusion

The findings of this study show that NWO was associated with high levels of CRP and IL6. Therefore, inflammatory pathways may play a role in the pathogenicity of NWO.

Transcriptomic and proteomic analyses provide insights into the adaptive responses to the combined impact of salinity and alkalinity in Gymnocypris przewalskii

Gymnocypris przewalskii is the only high-land endemic teleost living in Qinghai Lake, the largest saline-alkaline lake in China. Its osmoregulatory physiology remains elusive due to a lack of precise identification of the response proteins. In the present study, DIA/SWATH was used to identify differentially expressed proteins (DEPs) under alkaline (pH = 10.1, carbonate buffer), saline (12‰, sodium chloride), and saline-alkaline [carbonate buffer (pH = 10.1) plus 11‰ sodium chloride] stresses. A total of 66,056 unique peptides representing 7,150 proteins and 230 DEPs [the false discovery rate (FDR) ≤ 0.05, fold change (FC) ≥ 1.5] were identified under different stresses. Comparative analyses of the proteome and transcriptome indicated that over 86% of DEPs did not show consistent trends with mRNA. In addition to consistent enrichment results under different stresses, the specific DEPs involved in saline-alkaline adaptation were primarily enriched in functions of homeostasis, hormone synthesis and reactions of defense response, complement activation and reproductive development. Meanwhile, a protein-protein interaction (PPI) network analysis of these specific DEPs indicated that the hub genes were ITGAX, MMP9, C3, F2, CD74, BTK, ANXA1, NCKAP1L, and CASP8. This study accurately isolated the genes that respond to stress, and the results could be helpful for understanding the physiological regulation mechanisms regarding salinity, alkalinity, and salinity-alkalinity interactions.

Central Obesity Is Associated with Variations in TSH and ACTH Levels among Euthyroid Obese Individuals

INTRODUCTION

The interactions of central obesity and body composition with thyroid hormones and the hypothalamus-pituitary-adrenal (HPA) axis are unclear; both central obesity and body composition have an impact on energy homeostasis. Our study aimed to investigate the association between body composition and pituitary hormones, including the HPA axis and pituitary-thyroid axis, in a Chinese population of euthyroid overweight and obese individuals.

METHODS

This was a cross-sectional study. Overweight and obese patients who regularly visited the multidisciplinary team (MDT) for obesity at Peking University First Hospital were enrolled in the study. Thyroid function, morning serum ACTH and cortisol levels, thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), body composition, and metabolic indicators, including liver function and the lipid profile, were measured at the first visit. Statistical analysis was performed using SPSS version 21.0 (IBM, USA).

RESULTS

In total, 441 patients with overweight or obesity were enrolled (male/female, 123/318). Patients were assigned to four groups according to the thyroid-stimulating hormone (TSH) level stratified by quartiles, and increased body mass index (BMI) was revealed in the highest TSH quartile group (p=0.002). Hip circumference (HC) of patients in the highest TSH quartile group was significantly increased (p=0.021). Morning ACTH levels and fasting insulin levels were significantly elevated in patients in the highest TSH quartile group (p=0.027 for fasting insulin, p < 0.001 for ACTH). In the female subgroup, patients in the highest TSH quartile group showed increases in BMI (p=0.010), waist circumference (WC) (p=0.007), muscle mass of the lower extremities (p=0.020), fasting C-peptide (p=0.031), and ACTH (p=0.002). In the male subgroup, patients in the highest TSH quartile group exhibited higher BMI (p=0.017), HC (p=0.036), and ACTH (p=0.003). Among patients in the highest ACTH quartile group, there was an elevated proportion of males (p=0.003), and FT3 (p=0.005), fasting insulin (p=0.037), and cortisol (p < 0.001) levels were increased. Weight (p < 0.001), BMI (p < 0.001), WC (p < 0.001), HC (p < 0.001), muscle mass of the upper extremities (p=0.003), muscle mass of the lower extremities (p=0.005), and total muscle mass (p=0.003) were elevated in patients in the highest ACTH quartile group. HC was found to be an independent factor after adjustment for other confounders and was positively associated with the TSH level (p=0.004 for the regression model, B = 0.152, p=0.004).

CONCLUSIONS

BMI is positively correlated with TSH and ACTH levels in both male and female obese individuals. The ACTH level was positively associated with male sex and increased BMI and muscle mass. Hip circumference was an independent factor that was positively related to TSH levels.

Normal weight obesity and unaddressed cardiometabolic health risk-a narrative review

Normal weight obesity (NWO) is defined as having a normal body mass index (BMI), but a high body fat mass. There is growing interest in individuals with NWO, which is an underdiagnosed and understudied group, because of their increased risk for cardiometabolic morbidity and mortality. In this review, we summarized the definition, prevalence, etiology, pathophysiology, and cardiovascular outcomes seen in NWO. We have also summarized the available literature on interventions for NWO. There is a wide variation in the body fat percent cutoffs used to diagnose excess body fat. Hence, the prevalence rates of NWO vary between different populations and studies. It is estimated that about 30 million Americans have NWO and the worldwide prevalence ranges from 4.5% to 22%. Genetics, diet, and physical activity are related to NWO. However, etiological factors are not clear. Changes in body composition, inflammation, oxidative stress are present in NWO in comparison to normal weight lean (NWL) who have a normal BMI and normal body fat amount. Furthermore, cardiometabolic changes are observed and some are subclinical. Thus, screening for NWO will enhance the primary prevention of cardiovascular disease. Due to the use of various body fat percent cutoffs and methods to measure body fat, it is challenging to compare between studies. Researchers working in this field should ideally work towards developing standard body fat percent cutoffs for diagnosing NWO. There are many gaps in the literature on NWO unlike for overt obesity and future studies should explore the etiology, molecular mechanisms, and adipose tissue changes of NWO as well as conduct well planned and executed randomized controlled trials testing dietary, physical, and behavioral interventions for NWO in both males and females of different racial and age groups.