RESUMEN
OBJECTIVE: To compare the performance of glycated hemoglobin (HbA1c) and oral glucose tolerance test (OGTT) in diagnosing diabetes and pre-diabetes in the general population. METHODS: A total of 1416 subjects from Nanchang, Jiangxi Province and Wuhan, Hubei Province who have participated the 2010 Chinese Nutrition and Health Survey were studied and their HbA1c were measured. The glycemic levels and distribution of the subjects diagnosed with diabetes and pre-diabetes by OGTT and HbA1c were compared. Receiver operating characteristic curves were constructed to determine the sensitivity and specificity of HbA1c in detecting diabetes as defined by OGTT. RESULTS: According to the 1999 WHO criteria, 86 subjects were diagnosed with diabetes and 262 were with pre-diabetes. Comparing with OGTT, the sensitivity and specificity of HbA1c > or = 6.5% was 41.9% and 98.9%. Subjects with diabetes diagnosed by HbA1c and OGTT were not consistent, and they have different HbA1c level. The HbA1c level of 5.7% - 6.4% was associated with a sensitivity of 78.6% and a specificity of 55.1% in detecting impaired glucose regulation (IGR). Cases with pre-diabetes identified by HbA1c 5.7% - 6.4% were different from those with IGR. They had lower fasting glucose and 2-hour plasma glucose after glucose load than those with IGR. CONCLUSION: Among this studied population, HbA1c > or = 6.5% showed high specificity but low sensitivity for detecting glucose-defined diabetes. The performance of HbA1c of 5.7% -6.4% in screening pre-diabetes is poor.
Asunto(s)
Diabetes Mellitus/diagnóstico , Prueba de Tolerancia a la Glucosa , Hemoglobina Glucada , Estado Prediabético/diagnóstico , Pueblo Asiatico , Ayuno , Humanos , Tamizaje Masivo , Curva ROC , Sensibilidad y EspecificidadRESUMEN
High temperature stress occurs frequently in rice due to global warming. High-temperature hazard during the booting-flowering and grain-filling stages is one of the major factors limiting rice yield and quality. Here, we summarized the occurrence characteristics (identification, classification, region, and time) of high-temperature hazards, and the effects of high temperature on rice growth and development, including physiology, grain yield, and grain quality. Furthermore, we reviewed molecular biology aspects including quantitative trait locus mapping, transcriptome analysis, proteome analysis, and the monitoring, early warning, risk assessment of high-temperature hazards in rice. The defensive measures against high temperature in rice including selecting heat-resistant varieties, improving field management practices and spraying exogenous substances were intensively described. Finally, future research work on high-temperature hazards in rice was prospected to provide the scientific support for rice high-temperature defense, agricultural disaster reduction, and agricultural efficiency improvement.
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Oryza , Grano Comestible , Calor , Oryza/genética , Proteoma , TemperaturaRESUMEN
The spatial-temporal characteristics of thermal resources are the main factor controlling the spatial distribution patterns of double cropping rice. Based on daily average temperature data collected from 240 weather stations in Hunan, Jiangxi and Hubei provinces, our study analyzed the change characteristics of thermal resources during thermal growth period and safe growth period of double cropping rice in the middle and lower reaches of the Yangtze River. Furthermore, we quantified the change trends of spatial pattern for the rice cropping systems with different rice varieties and the northern limit of double cropping rice. The results indicated that the thermal resources of double cropping rice displayed a significant increasing trend during both thermal and safe growth periods, with an abrupt change in 2000 in terms of the Mann-Kendall test. The safe planting date of early rice advanced for 3-7 days and the safe heading date of late rice delayed for 2 days. Averagely, the safe growth period extended by about 7 days, and the planting northern limit of double cropping rice shifted 200 km northward, approaching to the latitude of 33° N. Meanwhile, many areas with cropping systems of 'early maturing early rice + mid-maturing late rice' and 'mid-maturing early rice + mid-maturing late rice' were replaced by 'mid-maturing early rice + late-maturing late rice'. Our study revealed the feasibility to shift the double cropping rice system northward and replace early and mid-maturing rice variety with mid and late maturing rice variety due to the increa-sing thermal resources during growth period of double cropping rice under climate change.