مجله غدد درون ریز و متابولیسم ایران
سال بیست و سوم شماره 3 (پیاپی 117، امرداد و شهریور 1400)

Physiological changes during pregnancy affect thyroid function and also free thyroxine (FT4) assay methods. These impacts make immunoassays unreliable for detecting hypothyroxinemia during pregnancy. Due to pregnant women’s adequate consumption of iodine in Iran, reference ranges of FT4 needs to be obtained for this group.

A total of 1077 Iranian pregnant women were randomly selected from health clinics in 12 provinces of Iran during all trimesters. Five hundred eighty-seven individuals were included in the study after applying the exclusion criteria to establish the reference range. Then, TSH, FT4, and TPOAB levels were examined.

The mean age of the participants was 27.6 ± 5.7 years, and the median urine iodine level was 236 μg/L (188-321). The 5th and 95th percentiles obtained for FT4 were 0.93 and 1.35 in the first trimester, 0.78 and 1.15 in the second trimester, and 0.77 and 1.15 ng/dl in the third trimester, respectively.

Due to the downward trend of the normal range of FT4 from the first to the third trimester of pregnancy, it seems necessary to consider the trimester-specific normal range for diagnosis and management of thyroid disease in Iranian pregnant women.

Neuroinflammation plays an important role in developing many neurological changes in diabetic patients. This study aimed to investigate the effect of aerobic exercise and melatonin on COX-2 expression in spinal cord tissue and behavioral responses to pain caused by diabetic neuropathy in a rat model.

Forty eight-week-old male Wistar rats (weight range 204 ± 11.3 g) were randomly divided into five groups of eight, including diabetic neuropathy (50 mg/kg streptozotocin intraperitoneal injection), diabetic neuropathy with melatonin administration (10 mg/kg  melatonin daily for six weeks), diabetic neuropathy with exercise (30 minutes of aerobic exercise at 15 meters per minute, five days a week for six weeks), diabetic neuropathy with melatonin administration and exercise, and controls. After confirmation of diabetic neuropathy with behavioral tests, the exercising and melatonin administration protocol was performed. The COX-2 gene expression level in spinal cord tissue was measured using the real-time technique. Also, one-way analysis of variance and Tukey's post hoc test were used for statistical analysis.

Exercise and melatonin decreased the sensitivity of the nervous system to thermal hyperalgesia and mechanical allodynia in the diabetic neuropathy with melatonin administration and exercise group (P =0.026). Also, the COX-2 gene expression level was significantly reduced in this group compared to the diabetic neuropathy group (P=0.001).

Aerobic exercise with melatonin injection modulates the COX-2 gene expression level and improves the sensitivity of nociceptors to pathogens. Aerobic exercise and melatonin administration are recommended for neuropathic pain in people with diabetes.

Diabetes mellitus is a metabolic disease that causes vascular wall damage and poor wound healing due to the excessive accumulation of glucose. Various investigations have been performed on increasing the diabetic wound healing rate. The present study aimed to evaluate the effects of Ammonia single-cell eukaryote extract in Zinex ointment compared to silver sulfadiazine ointment on increasing the diabetic wound closure rate.

This study was performed on 54 BALB/c transgenic mice. For type 2 diabetes induction, the animals were fed a high-fat diet for two weeks and followed by a single dose of Streptozotocin (STZ) (30 mg/kg) injection intraperitoneally. The excisional wound was created using the excisional wound splinting model and a biopsy punch. For diabetic wound treatment, 10% Ammonia extract in Zinex ointment and 1% silver sulfadiazine ointment were used every three days. Glucose and insulin serum levels were measured using a glucometer and an ELISA kit, respectively. Histopathological examinations were also performed using H&E methods.

Macroscopic observations indicated an increase in the wound closure rate in the Ammonia extract group compared to the other groups. Also, histopathological results showed a significantly decreased inflammation and increased re-epithelialization in the Ammonia extract treatment group compared to the silver sulfadiazine treatment and control groups. 

The results showed that Ammonia extract in Zinex ointment could improve the closure rate and re-epithelialization in diabetic rat wounds through inflammation reduction.

Chronic kidney disease (CKD) is one of the most debilitating non-communicable diseases (NCDs). Since the incidence of NCDs increases after menopause, this study aimed to investigate the relationship between menopausal age and CKD incidence among menopausal women.

This study was performed longitudinally, and the subjects were selected from among 3697 postmenopausal women participating in the Tehran Lipid and Glucose Study. Among the subjects, those whose menopausal age and chronic kidney disease information were not recorded and who had chronic kidney disease before the study were excluded. Finally, 2,080 postmenopausal women remained in the study. The Cox regression model was used for data analysis.

By the end of the study, CKD occurred in 1351 menopausal women. The overall mean age of menopause was reported at 49.9±5.0. The mean age of menopause was 50±0.5 years in the patients and 49.7±5.0 years in others. After modifying the extraneous variables, the results showed that every year increase of age at menopause increased the incidence of CKD by 10% after menopause, with the hazard ratio of 1.10 and the confidence interval of 95% (1.07-1.13).

Menopausal age is directly related to the incidence of chronic kidney disease after menopause. Given the importance of CKD in reducing the quality of life and increasing mortality in patients, special attention should be paid to women of higher menopausal age in screening programs related to CKD.

As a nitric oxide (NO) donor, nitrate administration improves renal function in male animals. This study aims to determine the effects of chronic administration of different doses of nitrate on kidney function in normal adult female rats by measuring serum urea and creatinine and assessing the estimated glomerular filtration rate (eGFR).

Two-month old female Wistar rats were divided into six groups (n=10/group): the control group received tap water, and five nitrate-treated groups received water containing 50, 100, 150, 250, and 500 mg/L sodium nitrate in their drinking water for six months. At the end of the study, body weight, serum urea, and serum creatinine were measured, and eGFR was calculated.

Serum urea levels decreased by 16.9% (P=0.037) at dose 100 mg/L and increased by 15% (P=0.064) and 24.7% (P=0.003) at doses 250 and 500 mg/L, respectively, after nitrate administration. Serum creatinine levels decreased only at dose 100 mg/L by 16.3% (P=0.002) after nitrate administration. Moreover, eGFR increased at dose 100 mg/L (11.5%, P=0.046), decreased at doses 250 (13.8%, P=0.018) and 500 (16.9%, P=0.004) mg/L, and remained constant at doses 50 and 150 mg/L after nitrate administration.

Chronic nitrate administration exerted multiphasic effects on renal function in female rats; i.e., the low dose had no effect, the intermediate dose had a protective effect, and the high dose had detrimental effects on renal function.

SARS-CoV-2 is a type of coronavirus that causes COVID-19 disease. The virus can infect various organs by triggering hormones, regulatory and messenger molecules, and immune-inflammatory responses. Given the vital role of thyroid in metabolism, it is important to understand the potential effects of SARS-CoV-2 on the thyroid gland. In this article, reports and studies examining the effects of SARS-CoV-2 infection on thyroid are reviewed, and possible effects of this virus on thyroid function are discussed. According to the available evidence, SARS-CoV-2 can adversely impact thyroid function directly by affecting the pituitary-thyroid axis or indirectly by triggering immune-inflammatory responses. COVID-19-dependent thyroid disorders have been biochemically observed in three forms: hypothyroidism, thyrotoxicosis, and nonthyroidal illness syndrome. Subacute thyroiditis has been one of the most common clinical conditions of SARS-CoV-2-dependent thyrotoxicosis. In addition, SARS-CoV-2 may cause recurrence of improved thyroid diseases or exacerbate current diseases. There is no evidence that thyroid disease, including thyroid cancer, increases the risk of COVID-19 or exacerbates its complications. According to current studies, COVID-19 medications, including glucocorticoids and anticoagulants, have no adverse effects on thyroid function in non-acute COVID-19 patients. Further studies are needed to investigate the interactions between SARS-CoV-2 infection and thyroid function.

Spexin, a novel neuropeptide with diverse physiological functions, can be a cardiovascular disease risk assessment biomarker. This study investigated the association between serum spexin concentration and cardiovascular risk factors in children and adolescents.

A search was conducted to collect studies between January 2007 and March 2021 in the PubMed, Embase, and Scopus databases. The keywords "neuropeptide Q" and "spexin," along with keywords related to diabetes, inflammation, metabolic syndrome, and cardiovascular disease, were used for the search.

A total of 11 full-text articles were included in the study. In six of the studies, the spexin level was lower in obese children and adolescents than in normal-weight individuals, and the difference was significant in four of them (p <0.05). An inverse relationship was observed between spexin and insulin resistance in six of the studies; however, no correlation was found between spexin and glucose in the studies. The results were contradictory regarding inflammation, but the positive correlation of spexin with anti-inflammatory agents showed the anti-inflammatory effects of this neuropeptide. Five of the studies investigated the relationship between spexin and cardiovascular diseases such as hypertension, and three of them showed a positive role for spexin in cardiovascular health. Also, one of the studies examined the effect of spexin on metabolic syndrome and confirmed the protective role of spexin.

It seems that this neuropeptide positively affects metabolic status, especially weight control and insulin resistance, in children and adolescents.