Aim:We reevaluated waist circumference as a diagnostic criterion of metabolic syndrome (MetS) in Japanese. Methods: We enrolled 5,571 subjects (3,148 men and 2,423 women) who had health check-ups in our center. The criterion was reevaluated using the positive predictive value of a receiver-operating characteristics (ROC) curve at 10 different hypothesized lengths of waist circumference with or without a cluster of risk factors. We also drew ROC curves based on the atherosclerotic findings of clinical examinations. Results: Based on the ROC curves, the optimal waist circumference cut-off was 85 cm in men and 80 cm in women. Using this 80 cm cut-off point in women, misdiagnosis rates of MetS were lowered ( 19.1-56.6%) compared to the cut-off point currently in use. Integrating the influence of height, namely by using a waist-to-height 2 ratio, misdiagnosis rates in shorter populations were decreased in both men and women. Conclusion: These data suggested an optimal waist circumference cut-off to improve the diagnostic probability of MetS in Japanese women of 80 cm, as well as the utility of an easily detected anthropometric index such as a waist-to-height (cm 100/cm) or waist-to-height 2 (cm 10,000/cm 2 ) ratio, determined as 51 in men and 52 in women, or 30 in men and 33 in women, respectively. J Atheroscler Thromb, 2008; 15:94-99.Key words; Metabolic syndrome (MetS), Waist circumference, ROC curve, Height and 90 cm in women, accompanied by at least two of the following three risk factors: dyslipidemia, raised blood pressure, and raised fasting glucose. Although the cut-off point for waist circumference was defined by unique evidence corresponding to visceral fat area obtained by computed tomography (CT) scanning in Japanese subjects 9) , the optimal waist circumference cut-off has now become controversial. Because overt visceral fat obesity in Japanese is relatively low especially in women, waist circumference might lead to misdiagnosis, even when other risk factors are clustered. In fact, data obtained from 692 subjects in a community-based cohort study 10) and 329 subjects in a population-based study 11) in Japan indicate that a shorter waist circumference cut-off than those currently used would be optimal.

ObjectivesGraves’ disease (GD) has been highlighted as a possible adverse effect of the respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccine. However, it is unknown if the SARS-CoV-2 vaccine disrupts thyroid autoimmunity. We aimed to present long-term follow-up of thyroid autoimmunity after the SARS-CoV-2 BNT162b2 mRNA vaccine.MethodsSerum samples collected from seventy Japanese healthcare workers at baseline, 32 weeks after the second dose (pre-third dose), and 4 weeks after the third dose of the vaccine were analyzed. The time courses of anti-SARS-CoV-2 spike immunoglobulin G (IgG) antibody, thyroid-stimulating hormone receptor antibody (TRAb), and thyroid function were evaluated. Anti-thyroglobulin antibodies (TgAb) and anti-thyroid peroxidase antibodies (TPOAb) were additionally evaluated in thirty-three participants.ResultsThe median age was 50 (IQR, 38-54) years and 69% were female. The median anti-spike IgG antibody titer was 17627 (IQR, 10898-24175) U/mL 4 weeks after the third dose. The mean TRAb was significantly increased from 0.81 (SD, 0.05) IU/L at baseline to 0.97 (SD, 0.30) IU/L 4 weeks after the third dose without functional changes. An increase in TRAb was positively associated with female sex (β = 0.32, P = 0.008) and low basal FT4 (β = -0.29, P = 0.02) and FT3 (β = -0.33, P = 0.004). TgAb was increased by the third dose. Increase in TgAb was associated with history of the thyroid diseases (β = 0.55, P <0.001).ConclusionsSARS-CoV-2 BNT162b2 mRNA vaccine can disrupt thyroid autoimmunity. Clinicians should consider the possibility that the SARS-CoV-2 vaccine may disrupt thyroid autoimmunity.