Recent studies have shown that using international guidelines to diagnose metabolic syndrome (MetS) may underestimate its prevalence in different Asian populations. This study aims to determine the validity of anthropometric indicators and appropriate cut-off values to predict MetS for Vietnamese adults. We analyzed data on 4701 adults across four regions of Vietnam. Four conventional and five novel anthropometric indexes were calculated. The area under a receiver operating characteristic (ROC) curve (AUC) and Youden’s J statistic were applied to evaluate the diagnostic ability and optimal cut-off values. Regardless of diagnostic criteria and gender, Abdominal volume index (AVI), Body roundness index (BRI), and Waist-height ratio (WHtR) had the highest AUC values, followed by Body mass index (BMI) and Waist-hip ratio (WHR). However, it was seen that differences among the AUC values of most indices were minor. In men, using International Diabetes Federation (IDF) criteria, the threshold of indices was 3.86 for BRI, 16.20 for AVI, 0.53 for WHtR, 22.40 for BMI, and 0.90 for WHR. In women, the threshold for these figures were 3.60, 12.80, 0.51, 23.58, and 0.85, respectively. It is recommended that health personnel in Vietnam should apply appropriate thresholds of anthropometry, which are lower than current international guidelines, for MetS screening to avoid under-diagnosis.

The rising health threat to healthcare workers (HCWs) demands innovative preventive solutions that are affordable, scalable, and easy to deploy, especially in resource-limited settings. This present study investigated the effects of Lactococcus lactis strain Plasma (LC-Plasma) intake on upper respiratory infection (URI)-like symptoms in a healthy healthcare-associated population in Vietnam. A randomized, placebo-controlled, double-blind, parallel-group clinical trial was conducted, integrating clinical symptom analysis with ex vivo immune response analysis of peripheral blood mononuclear cells (PBMCs). The study found that after 4 weeks of continuous oral LC-Plasma intake, participants in the LC-Plasma group had significantly fewer cumulative days of fever and fatigue than those in the Control group. Increased expression of interferon-stimulated genes (ISGs), particularly MxA, was observed in PBMC cultures from the LC-Plasma intake group. In PBMCs from LC-Plasma recipients classified as low IFN-α responders, the addition of CpG ODN 2216, a mild TLR9 agonist, significantly enhanced interferon-α production. Humoral factors derived from LC-Plasma-primed PBMCs demonstrated inhibitory effects on dengue virus replication in Huh-7 cells. These results suggest that LC-Plasma consumption by the healthcare-associated population reduces the severity of viral infection symptoms, notably fever and fatigue. Elevation of systemic antiviral immunity through activation of plasmacytoid dendritic cells (pDCs) to produce IFN-α and upregulation of ISG expression could be the mechanisms of action. Lactococcus lactis LC-Plasma supplementation, hence, presents a promising adjunctive approach to alleviate the burden of URI-like symptoms in low-resourced vulnerable populations.

Upper respiratory tract infections (URTIs) are highly prevalent and impose substantial individual and societal burdens. Plasmacytoid dendritic cells (pDCs) are major producers of type I interferons (IFNs) with antiviral activity. This study investigated whether CpG oligodeoxynucleotide-induced IFN-α production by peripheral blood mononuclear cells (PBMCs), a marker of pDC activity, was associated with subsequent occurrence of the common cold. Data from 41 healthy adults in the placebo arm of a randomized controlled trial were analyzed. CpG-induced IFN-α production was measured before a 4-week observation period, and participants were dichotomized into high and low IFN-α production groups based on the median value. The occurrence of common cold events and cold symptoms was assessed using daily self-reported symptom scores and body temperature records. Seven participants developed the common cold, all in the low group. The crude risk difference between the low and high groups was 0.333 (Miettinen–Nurminen 95% CI, 0.148–0.546; Fisher’s exact p = 0.009). The low group also showed higher risks for fever, plugged nose, and sore throat, while findings for the other symptoms were less conclusive. As a hypothesis-generating pilot study, these findings suggest that low TLR9-mediated IFN-α production may be associated with increased susceptibility to URTIs in healthy adults.