Relationship of gender and age on thyroid hormone parameters in a large Chinese population

ABSTRACT Objective This study aimed to present the impact of age and gender on thyroid hormone levels in a large Chinese population with sufficient iodine intake. Subjects and methods A total of 83643 individuals were included and were stratified by age and gender. The median, 2.5th and 97.5th of thyrotropin (TSH), free triiodothyronine (FT3), free thyroxine (FT4) and FT3/FT4 ratio were calculated for both genders for every decade from 18 to over 80 years. TSH, FT3, FT4, FT3/FT4 distribution in each age group was evaluated for females and males using smoothing splines in the generalized additive models (GAM). TSH concentrations were compared in the different age groups in gender. Results In the over 80s age group, the TSH level (median: 2.57 mIU/L, 2.5th-97.5th: 0.86-7.56 mIU/L) was significantly higher than other age groups, irrespective to gender (P<0.001). Females had a higher TSH value than males in all age groups (P<0.001). Results of the smoothing curves showed that TSH increased with age, FT3 concentration was higher in males than in females and the tendency of the FT3/FT4 ratio was basically similar to that of FT3. TSH concentration in the 50s age group (median 2.48 mIU/L for females versus 2.00 mIU/L for males) was significantly higher than that in the 30s age group (median 2.18 mIU/L for females versus median 1.85 mIU/L for males). Conclusions In accord with increasing TSH values during aging, females and older adults have lower FT3 values and lower FT3/FT4 ratios, while the FT4 values remain stable.

Isolation and Identification of Components in the Dihydroquercetin-Rich Extract from Larch Wood (Larix olgensis Henry)

Background: The finding that antioxidant dihydroquercetin (DHQ) present in high content in the wood of Dahurian larch (Larix gmelinii Rupr.) which distributes mainly in Khingan Mountains led to the development and manufacture of a DHQ-rich extract, Lavitol (a trade name). Whether the composition of DHQ-rich extract from L. olgensis Henry, a great resource of Larch species distributed in Changbai Mountain in China, is same or similar with trade DHQ product becomes an interesting question. Aims: To isolate and identify the components in the DHQ-rich extract from larch wood (L. olgensis). Methodology: Compounds were isolated from a DHQ-rich extract (91% purity) of L. olgensis through polyamide and Sephadex LH-20 column chromatography, and their structures were elucidated based on 1H-NMR, 13C-NMR, MS and CD data analysis. Thin layer chromatography (TLC) was applied to quickly identify the components in the extract. Results: Five compounds were isolated from the extract, the main one was (2R,3R)-dihydroquercetin (1), four minor components were identified as (2R,3R)-aromadendrin (2), quercetin (3), 3,5,7-trihydroxychromone (4) and (2R,3R)-3'-O-methyl-taxifolin (5). Polyamide and silica gel TLC were developed to identify these components in the extract, and the results indicated that three batches of DHQ-rich extracts contained the same components. Conclusion: Except for the presence of trace impurities 4 and 5, DHQ-rich extracts from L. olgensis contained (2R,3R)-DHQ (1) and two minor impurities 2 and 3, which were similar with the composition of trade DHQ-rich extract from Dahurian larch (L. gmelinii). Further quantification of these impurities in DHQ-rich extract from L. olgensis by HPLC analysis need to be done in the future.

Association between polymorphism of the G-protein β3 subunit C825T and essential hypertension: an updated meta-analysis involving 36,802 subjects

Purpose: The G-protein β3-subunit gene C825T polymorphism (GNB3-C825T) has been reported to be associated with essential hypertension (EH), but results from previous studies are conflicting. The present study aimed at investigating the association between this polymorphism and risk of EH using a meta-analysis on the published studies. Materials and Methods: PubMed, Embase, CBM (China Biological Medicine Database), Wanfang and VIP databases were searched to identify eligible studies published in English and Chinese before March 2013. Data were extracted using standardized methods. The association was assessed by the odds ratio (OR) with 95% confidence intervals (CI). Begg's test was used to measure publication bias. Results: A total of 40 case-control studies containing 16,518 EH patients and 20,284 controls were involved in this meta-analysis. Overall, a significant association was found between GNB3 C825T polymorphism and risk of EH when all studies were pooled with a random-effects model for T versus C (OR=1.09, 95% CI: 1.04-1.19). In the subgroup analysis, the same association was found in overall Caucasian (T versus C, OR=1.16, 95% CI 1.08-1.24) and Chinese populations (TT versus CC, OR=1.23, 95% CI 1.06-1.57). No associations were detected between GNB3-C825T and the risk of EH overall in Asian and Japanese people. Conclusions: Meta-analysis results suggest that the GNB3-C825T polymorphism is associated with risk of EH in the overall population, the Caucasians and the Chinese. The effect of the variants on the expression levels and the possible functional role of the variants in EH should be addressed in further studies.

Refinement of the locus for non-syndromic sensorineural deafness (DFN2).

Non-syndromic X-linked deafness is a rare form of genetic deafness in humans accounting for a small proportion of all hereditary hearing loss. Different clinical forms of non-syndromic X-linked deafness have been described, and most of these have been mapped. Here, we report a Chinese family affected by a congenital profound sensorineural hearing loss. All phenotypes of this family are clinically compatible with non-syndromic sensorineural deafness (DFN2). A maximum two-point Lod score of 2.32 was obtained at marker DXS6797 (theta = 0.00). Recombinants define a region of 4.3 cM flanked by markers DXS6799 and GATA172D05. This region overlaps the previously reported DFN2 region by 2.0 cM.