Differential Effects on HbA1c Detection by HPLC and Capillary Electrophoresis in Five Types of Hb Variants in China.

OBJECTIVE: Hemoglobin A1c (HbA1c) can be used to evaluate blood glucose control. Its measurement will be affected by many factors, but Hb variation is the most critical factor. This study aimed to explore the types of variants found in routine work and their impact on test results. METHODS: Samples with abnormal HbA1c chromatograms found in routine testing were tested with high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) and then further tested with polymerase chain reaction (PCR) and sequencing. RESULTS: Five recessive heterozygous mutations were identified after PCR and sequencing. Hb Riccarton-II (a mutation in the HBA2 gene), Hb E, Hb G-Coushatta, Hb G-Taipei, and Hb North Manchester (a mutation in the HbB gene) were identified. All HbA1c values of these variants detected by HLC-723 G8 (HPLC method) were lower than those of Sebia Capillarys 2 FP (C2FP, CE method) with P < .0001. CONCLUSION: Five Hb mutations were identified in our routine HbA1c test, and their HPLC detection values were significantly lower than those obtained with the CE method.

A Pitfall in HbA1c Testing Caused by Hb Long Island Hemoglobin Variant.

BACKGROUND: Although many factors may interfere with hemoglobin (Hb)A1c measurement, Hb variants are among the most important factors. METHODS: We tested the HbA1c levels of the patient, a 32 year old Manchu Chinese woman, during a routine health check. We used different methods, including high-performance liquid chromatography (HPLC) and capillary electrophoresis, to test specimens from the patient. Next, we tested the specimen further using polymerase chain reaction (PCR) and sequencing. RESULTS: We discovered that our patient, who had an HbA1c value of 0, also has an Hb variant, Hb Long Island, which we found during the HbA1c analysis as part of her routine health check at the Health Management Center in the General Hospital of Tianjin Medical University, Tianjin, China. Also, we discovered that the exon 1 of ß gene contained transversion mutations, with 1 heterozygous and 1 homozygous variant (HBB:c.8A > C, 9T > C). These gene mutations resulted in an amino-acid change (His to Pro) and a decrease in HbA1c value. CONCLUSIONS: When there is no correlation between the clinical signs, glycemic status, and glycated Hb levels of the patient, the chromatogram of HbA1c should be carefully checked to detect possible variants that cause interference in the measurement.

A clinical analysis of 123 cases of primary empty sella / 中华内科杂志

Objective This study was conducted to analyze the clinical characteristics and pituitary function of patients with primary empty sella (PES).Methods The clinical data from 123 hospitalized adult patients with PES from January 2010 to May 2016 were retrospectively studied.Results (1) The average age of the 123 (male 43,female 80) PES patients was (59.2 ± 13.6) years (ranging 24-92 years),among whom 61％ patients were in the age group between 50-69 years.(2) The symptoms of the patients included fatigue (56.1％),headache (34.1％),nausea and vomiting (17.9％),gonadal dysfunction (17.1％),visual disturbance (5.7％) and hypopituitarism crisis (3.3％).(3) Hypopituitarism was found in 66 of the 123 patients.Among them,36.6％,31.7％ and 17.1％ were central hypoadrenalism,hypogonadism,and hypothyroidism,respectively.The percentage of hypopituitarism in complete PES was significantly higher than that in partial PES (P ＜ 0.05).(4) Sixteen patients were concomitant with other autoimmune diseases including 11 patients with Graves' disease and 2 with Cushing's syndrome due to adrenal adenoma.Conclusions The incidence of hypopituitarism in PES was 53.7％,in which the pituitary-adrenal axis hypofunction was more common.An overall evaluation of the pituitary function was essential for the patients who had headache and fatigue,or with suspected PES.The patients with hypopituitarism should be given hormone replacement therapy in time and followed up afterword.

The relationship between thyroid autoantibodies and thyroid function in different populations / 中华内分泌代谢杂志

To explore the relationship between thyroid autoantibodies and thyroid function in school children aged 8-10 years,adults,pregnant women,and lactating women in China,in order to provide reference for the prevention and monitoring of thyroid disease.Healthy 8-10 years old school children (693 cases),adults (698 cases),pregnant women(325 cases),and lactating women(332 cases) from six iodine sufficient areas were enrolled.Serum TSH,FT4,and FT3 were determined by chemiluminescent immunoassay,while antithyroid antibody by radioimmunoassay.The positive rate of thyroid autoantibodies in females was significantly higher than that in the male (5.6％ vs 2.0％ in school children,and 22.8％ vs 3.2％ in adults) ; while positive rate of autoantibodies in pregnant and lactating women (8.9％,8.7％) were significantly lower than that in the other healthy adult women (22.8％).The incidence of abnormal thyroid function in antibody-positive people was higher than that in negative ones in all groups,and abnormal thyroid function showed mainly as subclinical hypothyroidism.In addition,lactating women with negative autoantibodies presented a higher incidence of abnormal thyroid function,mainly as low FT4.The abnormal thyroid function is related with the positive thyroid autoantibodies,indicating that it is essential to follow-up these people with positive antibodies in order to facilitate prevention,early diagnosis,and treatment of thyroid disease.Reference data for thyroid hormones in lactating women should be establisbed as soon as possible.

Analysis of urinary iodine levels in normal pregnant Chinese women in four districts / 中华内分泌代谢杂志

Objective To analyze the median urinary iodine(MUI)level in normal pregnant women based on World HeMth Organization(WHO) recommended criterion,and to provide the MUI reference values for monitoring and evaluating iodine nutrition during pregnancy and related studies.Methods Total 604 normal pregnant and 192 non-pregnant women(as a comparison)were selected from a cross-sectional survey.These women were all healthy,iodine sufficient,with normal thyroid function,and negative anti-thyroid antibodies.The iodine content in drinking water,edible salt,and urine was determined by standard methods,and serum TSH,FT4,FT3,thyroid peroxidaseantibody(TPOAb),and thyroglobulin antibody(TgAb)were measured using chemiluminescent immunoassay.Resuits (1)The iodine in drinking water was 3.0μg/L indicating such small amount of iodine could be neglected for daily iodine intake.(2)All women consumed iodized salt with the median iodine in salt of 31.7 mg/kg.The daily iodine intake of at least 240 μg could be roughly estimated if an average of 10 g salt was taken per person per day and further subtracted by 20%iodine lost during cooking,which could meet the iodine needs during pregnancy.(3)The MUI of 173.1μg/L was calculated from 604 pregnant women having 174.5,167.0,and 180.7 μg/L during the first,second,and third trimesters,respectively,reaching the optimal level of 150-249 μg/L recommended by WHO for pregnant women.However,our data showed relatively lower levels,not reaching 200μg/L.The MUI of 240.2μg/L was calculated from 192 non-pregnant women,reaching the level of"above requirement"(200-299μg/L) recommended by WHO for adults.(4)All women were euthyroid and antibody-negative,but the TSH level in pregnant women was lower than that in non-pregnant women,in particular during the first trimester,while FT4 and FT3 were considerably decreased compared with the non-pregnant(with an exception of FT4 in the first trimester),and both gradually declined with the gestational age.Conclusions The optimal MUI level of 150-249 μg/,L recommended by WHO can be applied to pregnant Chinese women,but our data provided a relatively low range of 150-200μ/L throughout pregnancy.The higher MUI of 240.2μg/L in non-pregnant women indicated that iodized salt with different contents should be supplied on market to meet the requirement of different groups of population.

The Relationship between Different Iodine Intake and Thyroid Function in Adults / 天津医药

Objective:To observe the effect of different iodine intake on the thyroid function in euthyroid adult persons.Methods:One hundred and sixty-one euthyroid healthy volunteers aged 18-24 years were randomly divided into 7 groups.Each group was assigned to receive 500 μg,750 μg,1 000 μg,1 250 μg,1 500 μg,and 2 000 μg iodide/day for four weeks.Serum concentrations of free triiodothyronine(FT3),free thyroxin(FT4)and sensitive thyroid-stimulating hormone(sTSH)were measured by chemolumineseenee assays.Results:Serum FT3 concentration was found a small decline within the normal range in all the iodide supplemented groups(P ＜ 0.05).The level of FT4 was significantly lower,when the dose was up to 1 500 μg (P ＜ 0.05).The level of serum sTSH was increased after 2 weeks iodide supplement in all groups,and after 4 weeks in 500 μg and 750 μg groups(P ＜ 0.05).No significant changes were observed in FT3,FT4 and sTSH between groups(P＞ 0.05).Conclusion:The thyroid function of normal people showed a rise in serum sTSH at a short time and a high-dose of iodine intake.

Trimester-specific reference data of thyroid hormones for normal pregnancy / 中华内分泌代谢杂志

Objective To set up the trimester-specific reference ranges of thyroid hormones for normal pregnant women to provide reference criteria for diagnosis, treatment and monitoring or screening of thyroid disease during pregnancy and related research. Methods A cross-sectional survey was conducted in pregnant and non-pregnant women in iodine sufficient areas. A total of 505 normal pregnant women and 153 normal non-pregnant women (as control) were selected for establishing trimester-specific reference ranges of thyroid hormones after rigorous screening through the survey questionnaire and laboratory tests. Thyroid hormones were measured by Bayer automated chemiluminescence immunoassay, and the reference range of each hormone was calculated as median (the 50th percentile value) and two-sided limits (the 2.5th and 97.5th percentile values). Results All women investigated were in iodine sufficient status within optimal urine iodine level. The serum TSH level during the 1st trimester was obviously declined compared with that in the non-pregnant individuals (P < 0.01), and started to rise during the 2nd trimester, but was still not restored to non-pregnant level until the 3rd trimester. Serum FT4 and FT3 levels gradually decreased from the 2nd trimester to the 3rd (P < 0.01), and the TT4 and TT3 levels were markedly elevated since early pregnancy (P < 0.01) and reached peak levels at the 2nd trimester approximately making up to 1.5 times of those in the non-pregnant individuals. Conclusion The thyroid hormone levels during pregnancy differ completely from those of the non-pregnant individuals, and also differ during different gestation periods. Therefore, to establish trimester-specific reference data of thyroid hormones during normal pregnancy may be important for clinical practice.