ABSTRACT
The burden of metabolic syndrome (MetS) has increased worldwide, especially during the COVID-19 pandemic, and this phenomenon is related to environmental, dietary, and lifestyle risk factors. We aimed to determine the association between the levels of serum heavy metals, hs-CRP, vitamins, and curry intake and to predict risks of MetS based on marginal effects. A data set of 60,256 Koreans aged ≥ 15 years between 2009 and 2017 was used to obtain information on sociodemographic, lifestyle, family history characteristics, MetS, food intake survey, and serum heavy metals. Daily intake of vitamins was measured by a one-day 24 h recall, and curry consumption was calculated using a food frequency questionnaire. Serum heavy metal levels were quantified by graphite furnace atomic absorption spectrometry and using a mercury analyzer. We found that vitamin B1, B2, B3, C, and A intakes were significantly lower in subjects with than without MetS. In contrast, serum levels of Pb, Hg, Cd, vitamin A, E, and hs-CRP were significantly higher in subjects with MetS. The risk of MetS was significantly lower for high curry consumers than low curry consumers (adjusted odds ratio 0.85, 95%CI 0.74-0.98). The risks of MetS were reduced by 12% and 1%, when vitamin B1 and C intakes increased by one mg, respectively, but were increased by 14%, 3%, and 9%, when serum levels of Pb, Hg, and hs-CRP increased by one unit. These results show that the potential health benefits resulting from vitamin and curry intakes could protect the public against the dual burden of communicable and non-communicable diseases. Further studies are required to reduce risk factors associated with serum heavy metal levels and to determine whether interactions between vitamin and curry consumption influence the presence of MetS.
ABSTRACT
The COVID-19, caused by the novel coronavirus SARS-CoV-2, has broken out of control all over the globe and put the majority of the world under lockdown. There have been no specific antiviral medications for SARS-CoV-2 while vaccines are still under development. Thus, rapid diagnosis and necessary public health measures are currently key parts to contain the pandemic. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) is the gold standard method for SARS-CoV-2 detection. However, this method is not suitable for point-of-care (POC) diagnosis because of the timeconsuming procedure, the requirements of biosafety conditions and expensive equipment. In this study, the colorimetric isothermal nucleic acid amplification tests (iNAATs) for SARS-CoV-2 based on loop-mediated isothermal amplification (LAMP), cross-priming amplification (CPA), and polymerase spiral reaction (PSR) were developed and compared. The three methods exhibited similar performance with the limit of detection (LOD) as low as just 1 copy per reaction when evaluated on the synthetic DNA fragments. The results can be read with naked eyes within 30 minutes without crossreactivity to closely related coronaviruses. When tested with SARS-CoV-2 extracted genomic-RNA, LAMP outperformed both CPA and PSR assays. Moreover, the direct detection of SARS-CoV-2 in simulated patient samples (oropharyngeal and nasopharyngeal swabs) by colorimetric iNAATs was also successful. Further preparation of the lyophilized reagents for LAMP reactions revealed that the freeze-dried, ready-to-use kit maintained the sensitivity and LOD value of the liquid assays. These results strongly indicate that the colorimetric lyophilized LAMP test kit developed herein is highly suitable for detecting SARS-CoV-2 at POC.