The impact of chronic disease diagnoses on smoking behavior change and maintenance: Evidence from China.

INTRODUCTION: Managing chronic diseases and tobacco use is a formidable challenge in low- and middle-income countries (LMICs) with limited health literacy and access to quality healthcare. This study examines the empirical evidence from China, utilizing quasi-experimental approaches to assess the causal effect of chronic disease diagnoses on smoking behavior. METHODS: Employing the diagnosis of chronic disease in the older cohorts of the population as a natural experiment, this study utilizes recent advancements in difference-in-difference estimation methods (CS-DID) to investigate the effect of a diagnosis on smoking behavior. Self-reported new diagnoses of conditions ascertained chronic disease diagnoses. CS-DID was run using the study sample from the 2011 to 2018 waves of the China Health and Retirement Longitudinal Study, comparing results with traditional two-way fixed effects and event-study models. RESULTS: The average treatment effect (ATT) of CS-DID is slightly greater than the effects reported using conventional difference-in-difference methods. We found that diagnoses of cancer, heart disease, and stroke reduced smoking rates by 16% (95% CI: -24 - -8), smoking intensity by 0.31 (95% CI: -0.46 - -0.15), and had lasting impacts on smoking cessation behavior (one wave after diagnosis ATT= -0.17; 95% CI: -0.34 - -0.00, two waves after diagnosis ATT= -0.17; 95% CI: -0.37-0.03). A diagnosis of a mild chronic disease, such as hypertension, diabetes, asthma, chronic lung disease, liver disease, or gastric disease, had more negligible and transient effects on smoking behavior. CONCLUSIONS: Efforts to enhance smoking cessation in middle-aged and elderly patients with chronic diseases are crucial to improving health outcomes. The 'teachable moment' of chronic disease diagnosis should be seized to provide smoking cessation assistance to achieve the goal of healthy ageing.

Effects of acupuncture synchronized rehabilitation therapy on upper limb motor and sensory function after stroke: a study protocol for a single-center, 2 × 2 factorial design, randomized controlled trial.

Background: Upper limb function reconstruction has been an important issue in the field of stroke rehabilitation. Due to the complexity of upper extremity dysfunction in stroke patients, the clinical efficacy produced by central or peripheral stimulation alone is limited. For this reason, our group has proposed acupuncture synchronized rehabilitation therapy (ASRT), i.e., simultaneous scalp acupuncture and intradermal acupuncture during rehabilitation. Pre-experiments results showed that this therapy can effectively improve the motor and sensory functions of upper limbs in post-stroke patients, but the clinical efficacy and safety of ASRT need to be further verified, and whether there is a synergistic effect between scalp acupuncture and intradermal acupuncture also needs to be studied in depth. Therefore, we designed a randomized controlled trial to compare the efficacy and safety of different therapies to explore a more scientific "synchronous treatment model." Methods: This is a single-center, randomized controlled trial using a 2 × 2 factorial design. We will recruit 136 stroke survivors with upper extremity dysfunction and randomize them into four groups (n = 34). All subjects will undergo routine treatment, based on which the Experimental Group 1: rehabilitation training synchronized with intradermal acupuncture treatment of the affected upper limb; Experimental Group 2: rehabilitation training of the affected upper limb synchronized with focal-side scalp acupuncture treatment, and Experimental Group 3: rehabilitation training synchronized with intradermal acupuncture treatment of the affected upper limb synchronized with focal-side scalp acupuncture treatment; Control Group: rehabilitation training of the affected upper limb only. The intervention will last for 4 weeks, 5 times a week. Both acupuncture treatments will be performed according to the Revised Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA). The primary outcome indicators for this trial are Fugl-Meyer Assessment-Upper Extremity and Somatosensory Evoked Potential. Secondary outcome indicators include Wolf Motor Function Test, Upper Extremity Function Test, revised Nottingham Sensory Assessment Scale, Diffusion Tensor Imaging, and Modified Barthel Index. The incidence of adverse events will be used as the indicator of safety. Discussion: The study will provide high-quality clinical evidence on whether ASRT improves upper limb motor and sensory function and activities of daily living (ADL) in stroke patients, and determine whether scalp acupuncture and intradermal acupuncture have synergistic effects. Clinical trial registration: https://www.chictr.org.cn/, Chinese Clinical Trial Registry [ChiCTR2200066646].

Effect of yhfS gene on Bt LLP29 antioxidant and UV ray resistance.

BACKGROUND: Bacillus thuringiensis (Bt) is a widely used microbial insecticide. However, its persistence is limited because of ultraviolet (UV) rays or other environmental factors. The yhfS gene, which encodes acetyl-CoA acyltransferase, plays an important role in lipid transport and metabolism in many organisms. To explore whether it is related to the stress resistance of Bt LLP29, the yhfS gene knockout strain LLP29 Δ-yhfS and the complementary strain LLP29 R-yhfS were generated successfully by homologous recombination technology, and the related phenotypic changes were compared in this study. RESULTS: Gene yhfS was found to be functional in response to UV radiation in Bt by comparing the survival rates of Bt LLP29 harboring yhfS or not under UV light. Enzyme activity assays of key enzymes showed the the Embden-Meyerhof-Parnas pathway was enhanced yet the tricarboxylic acid cycle as well as butanoate synthesis were repressed when the gene was deleted. At the same time, the amino acid content was decreased, but reduced nicotinamide adenine dinucleotide (NADH) and reactive oxygen species (ROS) content were increased. Most noteworthy, antioxidase (such as superoxide dismutase and peroxidase) activities and contents of some potent antioxidants (such as pyruvate, carotenoids and NADPH) were lower in LLP29 Δ-yhfS than in LLP29. CONCLUSION: These tests revealed that the loss of the yhfS gene led to metabolic disorders and reduction of the antioxidant ability of Bt. Higher ROS level and lower anti-oxidative capacity might be responsible for the reduced UV resistance when the gene was deleted. These results not only greatly enrich understanding of the mechanism of Bt UV resistance, but also provide an important theoretical basis for Bt application. © 2023 Society of Chemical Industry.

Effect of Zhan Zhuang Qigong on upper limb static tremor and aerobic exercise capacity in patients with mild-to-moderate Parkinson's disease: study protocol for a randomised controlled trial.

INTRODUCTION: Currently, the first choice for the clinical treatment of static tremor in Parkinson's disease (PD) is drug therapy, however side effects are common. In recent years, the effects of physical therapy on PD has become a serious research focus. Studies have indicated that aerobic and resistance exercises alleviate PD movement disorders and improve aerobic capacity, but the effects of Qigong on PD static tremor and aerobic capacity remain unknown. METHODS AND ANALYSIS: OBJECTIVE: To observe the effects of Zhan Zhuang Qigong on upper limb static tremor and aerobic capacity in patients with PD, we established a rigorous randomised, parallel-controlled, assignment hidden, evaluator-blinded protocol. METHODS: Seventy-two patients with PD, at the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, were recruited and randomly divided into a control (n=36) and experimental group (n=36). The intervention group received conventional medicine plus Zhan Zhuang Qigong exercises five times a week at 30 min each time, over an 8-week period. The long-term effects of Zhan Zhuang Qigong on PD was investigated after the intervention. Phyphox APP, CRST, CPET, UPDRS(II, III) were used to evaluate tremor, aerobic capacity, and motor function in groups. DISCUSSION: We are investigating the effects of Zhan Zhuang Qigong on upper limb static tremor and aerobic capacity in patients with PD. If positive are identified, they will add a new research direction and evidence for the clinical exploration of exercise therapy for PD. ETHICS AND DISSEMINATION: This study was approved by the Ethics Committee of Shandong University of Traditional Chinese Medicine (Approval Number: 2021-025-KY). The Committee will be informed of any changes to the trial protocol, such as intervention intensity, outcome indicators and data collection. Study results will be presented as a paper at an international conference or in a journal. TRIAL REGISTRATION NUMBER: ChiCTR2100053529.

Implication of the hepatokine, fibrinogen-like protein 1 in liver diseases, metabolic disorders and cancer: The need to harness its full potential.

Fibrinogen-like protein 1 (FGL1) is a novel hepatokine that forms part of the fibrinogen superfamily. It is predominantly expressed in the liver under normal physiological conditions. When the liver is injured by external factors, such as chemical drugs and radiation, FGL1 acts as a protective factor to promote the growth of regenerated cells. However, elevated hepatic FGL1 under high fat conditions can cause lipid accumulation and inflammation, which in turn trigger the development of non-alcoholic fatty liver disease, diabetes, and obesity. FGL1 is also involved in the regulation of insulin resistance in adipose tissues and skeletal muscles as a means of communication between the liver and other tissues. In addition, the abnormally changed FGL1 levels in the plasma of cancer patients make it a potential predictor of cancer incidence in clinical practice. FGL1 was recently identified as a major functional ligand of the immune inhibitory receptor, lymphocyte-activation gene 3 (LAG3), thus making it a promising target for cancer immunotherapy except for the classical programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) axis. Despite the potential of FGL1 as a new cancer biomarker and therapeutic target, there are few related studies and much of what has been reported are superficial and lack depth and particularity. Therefore, elucidating the role and underlying mechanisms of FGL1 could be crucial for the development of promising diagnostic and therapeutic strategies for related diseases. Here, we provide a comprehensive review of the cellular mechanisms and clinical prospects of FGL1 in the prevention and treatment of liver diseases, metabolic disorders and cancer, and proffer suggestions for future studies.

Does the Development of the Insurance Industry Promote the Purchase of Rural Commercial Health Insurance?

Deepening the reform of insurance companies and improving commercial insurance protection capabilities become issues important to national strategy. They involve improving China's multi-tiered social security system to analyze the deep-seated reasons impacting the purchasing behavior of commercial health insurance for rural residents in China. Using the DEA-CCR model, this paper evaluates the development of China's insurance industry, inspects the impact of insurance industry development on purchasing behavior of rural commercial health insurance based on the data of tracking survey projects from China's household, and carries out empirical analysis. The research result shows that the development of the insurance industry has obviously promoted the purchase behavior of commercial health insurance for rural residents. This research has significant practical value on protection and promotion of production and life quality of rural residents, which will also provide beneficial reference on the formulation and implementation of future operation strategy in China's commercial health insurance companies.

Can Physical Exercise Improve the Residents' Health?

With the rapid development of China's economy and society, the quality of life of residents has continued to improve, and the concept of health has gradually taken root in the hearts of the people. This paper uses the 2018 data of the China Family Panel Studies (CFPS) to analyze the internal mechanism and influencing factors of participating in physical exercise on the health level of residents. The results show that participating in physical exercise can significantly improve the subjective and objective health level of residents, and the result passed two important robustness tests. Heterogeneous test shows that the degree of influence of participation in physical exercise on the health level of residents varies according to the different regional and individual characteristics; the effect of urban residents' physical exercise to improve their health level is better than that of rural residents; and the effect of physical exercise on the improvement of health level is more obvious in the eastern and western areas, those who have not completed compulsory education, and those with high incomes. This study will have strong guiding significance for the improvement of the overall level of national health in China and will provide a theoretical basis and guiding opinions for the construction of healthy China.

Measuring Multidimensional Health Poverty in China.

This article defines the concept of "multidimensional health poverty," considering both the monetary aspects and multidimensional health deprivation of health poverty. Moreover, we set up the multidimensional health poverty index (MHPI) to measure health poverty in China by revising the traditional A-F MPI method, specifically we use the Catastrophic Health Expenditure (CHE) as a sufficient condition and income poverty as a necessary condition, and take physical, mental, and social health into account. The measurement result evidences that physical health, monetary dimensions (CHE and income poverty), and mental health contribute most to health poverty in China. In addition, the MHPI is significantly higher in rural areas than urban because of higher out-of-pocket medical payments and health deprivation in more dimensions. Compared with the traditional method, the MHPI is more accurate, stable, and comprehensive, making it more suitable for measuring health poverty.

Effects of long-term excessive iodine intake on blood lipids in Chinese adults: a cross-sectional study.

OBJECTIVE: The aim of this study was to evaluate the effects of long-term excessive iodine intake on blood lipids in adults. METHODS: Three counties from Dezhou city and Liaocheng city in the Shandong province of China were selected as survey locations. Three to five villages were selected from each county and then categorized by the iodine concentration detected in the groundwater into Low (<10 µg/L), Medium (10-150 µg/L), High (150-300 µg/L), and Excessive (>300 µg/L) groups. A self-reported questionnaire was completed by each subject to provide demographic characteristics. Body height, weight, and blood pressure were recorded by trained staff. Blood lipids were measured. RESULTS: A total of 2156 subjects were recruited for the final analysis. The serum triglyceride (TRIG) was significantly higher in the Excessive group than in the other three groups (P < 0.05). Total cholesterol (TCHOL) and low-density lipoprotein-cholesterol (LDL-C) showed downward trends with the increases in the water iodine concentration. A statistical significance of the crude correlation coefficient was detected between the water iodine concentration and the TRIG, TCHOL, or LDL-C (P < 0.05). A significant correlation was also noted between the water iodine concentration and TCHOL or LDL-C after adjustment for covariates. High iodine concentration was a significant protective factor for TCHOL and LDL-C in adults, whereas elevated BMI and advancing age were risk factors for both variables. CONCLUSION: An association was identified between iodine excess and low TCHOL or LDL-C. In areas with excessive iodine, iodine intake should be considered in studies examining the factors that influence blood lipids.

Globalization, sustainable development, and variation in cost of power plant technologies: A perspective of developing economies.

This study evaluates the sustainable power plant cost in the outlook of global power plant efficiency to reduce fossil fuel dependency and greenhouse gas emissions. For this purpose, the Global Change Assessment Model (GCAM) applied for conducting the cost assessment of power zone technologies for all principal electricity generation. This study considers the characteristics of essential factors (cement, price of resources, possible increases in employees, and metals) that affect costs. This study suggests that the cost of electricity-generating technologies significantly affects growth efficiency, reduction in production cost, and improving environmental conditions. It also suggests that the cost of electricity-generating technologies, combined with technology mixture, is the key factor behind replacing existing technology in the electricity sector. EPRI cost assessments expanded by around 30% and 50% during 2015-2016. Factors like competition amongst power plant owners, the ambiguous marketplace, production procedures, and lack of environment-related strategies have resulted in massive environmental degradation in developing economies like Pakistan. Based on empirical findings, this study recommends designing efficient technologies, which would reduce power plant costs and ensure vertical prospects related to environmental conditions in the future.

Financial Development and Environmental Regulations: The Two Pillars of Green Transformation in China.

Awareness of the influence of environmental regulations and financial development on green technological progress by Chinese enterprises will help to promote the green transformation of China's economy, thereby comprehensively enhancing the quality and competitiveness of its economic development. This paper constructs a theoretical framework to analyze environmental regulation, financial development, and green technological progress and studies the relationship among these three indicators using 2004-2018 data from Shandong province. The results show that environmental regulations and financial development both play roles in promoting green technological progress, but as environmental regulation becomes stronger, the effects of finance on green technological progress begin to differ across regions. The results partially verify the applicability of the Porter hypothesis in China, providing a reference for all levels of government to formulate scientific and reasonable environmental rules and policies.

The relationship between urbanization, technology innovation, trade openness, and CO2 emissions: evidence from a panel of Asian countries.

This paper explores the dynamic relationship between CO2 emissions, urbanization, trade openness, and technology innovation based on the panel data of 13 Asian countries over the period of 1985-2019. The STIRPAT model is used as a framework for the analysis. For estimation purpose, panel cointegration and FMOLS techniques are utilized. The causality between the concerned variables is also examined by estimating a panel VECM model. The results of panel cointegration reveal the presence of long-run relationship among the variables. FMOLS estimations show that energy consumption increases CO2 emissions while technology change, urbanization, and trade openness compact it. Panel causality analysis indicates bidirectional causality between urbanization and emissions, technology and emissions, trade and emissions, and trade and technology in the long run. Overall findings support the idea that urbanization, technology innovation, and trade openness can play important role to achieve environmental sustainability.

Does asymmetric persistence in convergence of the air quality index (AQI) exist in China?

In recent years, China's air pollution has caused significant concern in the academia. China is the hub of business and financial activities, with the most populous cities. It is important to determine the convergence and asymmetric persistence of air quality index (AQI hereafter) in China to achieve sustainable development goals, especially the ones related to the environment. This paper uses the Fourier quantile unit root test to check for inter-regional convergence of monthly AQI for 74 cities across China from January 2013 to July 2019. For a comparative baseline analysis, five conventional univariate and quantile unit root tests are also conducted. The empirical outcomes show that the Fourier quantile unit test exhibits a significant advantage in detecting smooth breaks and evaluating the asymmetric behavior and mean-reverting properties of AQI. Moreover, the monthly AQI in 70 out of 74 C0hinese cities are stationary processes. These findings not only focus on the appropriate use of relevant modeling techniques of smooth breaks and asymmetries in the AQI series of the 74 Chinese cities but also provide crucial environmental sustainability and economic implications for AQI regulation policies.

Volatile aroma compounds in wines from Chinese wild/hybrid species.

The volatile aroma compounds in wines produced from Chinese wild/hybrid species were investigated in comparison to wines from European grapes. Volatiles were extracted by headspace solid-phase micro-extraction and identified by gas-chromatography/mass-spectrometry. The identification of analyte was performed by a combination of the linear retention index approach with the comparison of the obtained mass spectra. A total of 98 peaks were tentatively assigned as wine aroma components, and 15 odorants can be found at concentrations above their odor threshold among the odor activity values (OAVs) of 46 compounds evaluated in all of the wines. The "OAVs' aroma wheels" showed that the classes of aromatic series are first fruity, next herbaceous and roasty and no spicy and caramelized notes. Via principal component analysis, all the grape germplasm studied could be divided into four groups: "Jingsheng-1," "Cabernet Gernischt," "Beibinghong," and others, which exhibited distinctive aroma features, respectively. Practical applications Chinese wild grape species have many desirable properties for wine grape breeding such as possessing strong resistant genes to fungal diseases and cold condition, especially after hybridization with European grapes. As an emerging wine country, wines from Chinese wild/hybrid species have achieved much success in the last few years. The chemical content and biological properties have been studied extensively in many but there are a few studies in our knowledge about the wine tastes of these species. In this paper, the key odorants in wines produced from the Chinese grape species of V. amurensis Rupr., V. davidii Foex., and V. quinquangularis Rehd. and its hybrids were characterized in comparison to wines produced from European grapes (V. vinifera). The findings will help to the further understanding of the key aroma components in the different Chinese grapevine germplasm, and make further efforts to enrich the wine types in the marketplace.

Early constraint-induced movement therapy affects behavior and neuronal plasticity in ischemia-injured rat brains.

Constraint-induced movement therapy is an effective rehabilitative training technique used to improve the restoration of impaired upper extremity movement after stroke. However, whether constraint-induced movement therapy is more effective than conventional rehabilitation in acute or sub-acute stroke remains controversial. The aim of the present study was to identify the optimal time to start constraint-induced movement therapy after ischemic stroke and to explore the mechanisms by which constraint-induced movement therapy leads to post-stroke recovery. Sixty-four adult male Sprague-Dawley rats were randomly divided into four groups: sham-surgery group, cerebral ischemia/reperfusion group, early constraint-induced movement therapy group, and late constraint-induced movement therapy group. Rat models of left middle cerebral artery occlusion were established according to the Zea Longa line embolism method. Constraint-induced movement therapy was conducted starting on day 1 or day 14 in the early constraint-induced movement therapy and late constraint-induced movement therapy groups, respectively. To explore the effect of each intervention time on neuromotor function, behavioral function was assessed using a balance beam walking test before surgery and at 8 and 21 days after surgery. The expression levels of brain-derived neurotrophic factor, nerve growth factor and Nogo receptor were evaluated using real time-polymerase chain reaction and western blot assay to assess the effect of each intervention time. The results showed that the behavioral score was significantly lower in the early constraint-induced movement therapy group than in the cerebral ischemia/reperfusion and late constraint-induced movement therapy groups at 8 days. At 21 days, the scores had significantly decreased in the early constraint-induced movement therapy and late constraint-induced movement therapy groups. At 8 days, only mild pyknosis appeared in neurons of the ischemic penumbra in the early constraint-induced movement therapy group, which was distinctly better than in the cerebral ischemia/reperfusion group. At 21 days, only a few vacuolated cells were observed and no obvious inflammatory cells were visible in late constraint-induced movement therapy group, which was much better than at 8 days. The mRNA and protein expression levels of brain-derived neurotrophic factor and nerve growth factor were significantly higher, but expression levels of Nogo receptor were significantly lower in the early constraint-induced movement therapy group compared with the cerebral ischemia/reperfusion and late constraint-induced movement therapy groups at 8 days. The changes in expression levels at 21 days were larger but similar in both the early constraint-induced movement therapy and late constraint-induced movement therapy groups. Besides, the protein nerve growth factor level was higher in the late constraint-induced movement therapy group than in the early constraint-induced movement therapy group at 21 days. These results suggest that both early (1 day) and late (14 days) constraint-induced movement therapy induces molecular plasticity and facilitates functional recovery after ischemic stroke, as illustrated by the histology. The mechanism may be associated with downregulation of Nogo receptor expression and upregulation of brain-derived neurotrophic factor and nerve growth factor expression.

Constraint-induced movement therapy in treatment of acute and sub-acute stroke: a meta-analysis of 16 randomized controlled trials.

OBJECTIVE: The aim of this meta-analysis was to evaluate the clinical efficacy of constraint-induced movement therapy in acute and sub-acute stroke. DATA SOURCES: The key words were stroke, cerebrovascular accident, constraint-induced therapy, forced use, and randomized controlled trial. The databases, including China National Knowledge Infrastructure, WanFang, Weipu Information Resources System, Chinese Biomedical Literature Database, PubMed, Medline, Embase, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews, were searched for studies on randomized controlled trials for treating acute or sub-acute stroke published before March 2016. DATA SELECTION: We retrieved relevant randomized controlled trials that compared constraint-induced movement therapy in treatment of acute or sub-acute stroke with traditional rehabilitation therapy (traditional occupational therapy). Patients were older than 18 years, had disease courses less than 6 months, and were evaluated with at least one upper extremity function scale. Study quality was evaluated, and data that met the criteria were extracted. Stata 11.0 software was used for the meta-analysis. OUTCOME MEASURES: Fugl-Meyer motor assessment of the arm, the action research-arm test, a motor activity log for amount of use and quality of movement, the Wolf motor function test, and a modified Barthel index. RESULTS: A total of 16 prospective randomized controlled trials (379 patients in the constraint-induced movement-therapy group and 359 in the control group) met inclusion criteria. Analysis showed significant mean differences in favor of constraint-induced movement therapy for the Fugl-Meyer motor assessment of the arm (weighted mean difference (WMD) = 10.822; 95% confidence intervals (95% CI): 7.419-14.226), the action research-arm test (WMD = 10.718; 95% CI: 5.704-15.733), the motor activity log for amount of use and quality of movement (WMD = 0.812; 95% CI: 0.331-1.293) and the modified Barthel index (WMD = 10.706; 95% CI: 4.417-16.966). CONCLUSION: Constraint-induced movement therapy may be more beneficial than traditional rehabilitation therapy for improving upper limb function after acute or sub-acute stroke.

The complete mitochondrial genome of comma, polygonia c-aureum (Lepidoptera: Nymphalidae: Nymphalinae).

The mitochondrial genome (mitogenome) of Polygonia c-aureum (Lepidoptera: Nymphalidae: Nymphalinae) is determined to be 15,209 bp in length and shows AT bias (80.6%). Similar to other butterflies, it contains 37 typical mitochondrial genes and one AT-rich region (D-loop). All protein-coding genes (PCGs) started with ATN, except for cox1 gene with CGA(R), which is often found in other butterflies, and seven PCGs harbour the typical stop codon TAA, whereas cox1, cox2, nad3, nad5, nad4 and nad1 end with a single T. The rrnL and rrnS genes are 1332 bp and 773 bp in length, respectively. The 342 bp AT-rich region contains non-repetitive sequences, but harbour several features common to the lepidopterans, including the motif ATAGA followed by a 19-bp poly-T stretch and a microsatellite-like (TA)8 element preceded by the ATTTA motif. The complete mitogenome sequence provided here would be useful for further understanding the taxonomy and phylogeny of Nymphalinae.

Effect of combined excess iodine and low-protein diet on thyroid hormones and ultrastructure in Wistar rats.

The aim of the present study was to illustrate the combined effect of excess iodine and low-protein diet on the thyroid, and the potential molecular mechanism of this effect. One hundred ninety-two Wistar rats were randomly divided into the following groups: normal; 10- (10HI), 50- (50HI), or 100-fold excess iodine (100HI); low-protein; and low-protein combined with 10- (L10HI), 50- (L50HI), or 100-fold excess iodine (L100HI). At the end of 2, 4, or 6 months, the rats were sacrificed for iodine concentration and thyroid hormone analyses. The histological appearance of the thyroid gland was observed at the end of 6 months. At the end of 6 months, the serum total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3), and free triiodothyronine (FT3) levels in the 100HI, L10HI, L50HI, and L100HI groups were significantly lower than the control group (P < 0.05 or P < 0.01). Serum TT4, FT4, TT3, and FT3 levels in the low-protein excess iodine groups were significantly lower than the groups with an equal amount of excess iodine alone (P < 0.05 or P < 0.01). Light and electron microscopy showed that excess iodine caused damage to the ultrastructure of thyroid and apoptosis of follicular epithelial cells. In the 100HI, L50HI, and L100HI groups, thyroid follicular epithelial cells became flattened, and follicles became distended with colloid. The damage was more serious in low-protein groups. The present findings demonstrated that the low-protein diet aggravated the damage to the thyroid caused by excess iodine alone.