Table 2.
Characteristics and diagnosis criteria of the 15 included studies.
| Author | Year | Country | Study Design | Sample size | Gender (M / F) | MetS Diagnosis Criterion | Thyroid Nodule Diagnosis Criterion | Quality assessment | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Abdominal obesity | TG | HDL-C | Blood Pressure | Glucose | ||||||||
| Ayturk | 2009 | Turkey | case–control | 539 | —— | >102 cm in men, >88 cm in wemen | ≥ 1.7 mmol/L (150 mg/dl) or greater | Both men and women < 1.03 mmol/L (40 mg/dl) | ≥ 130/85 mmHg | FPG ≥ 6.1 mmol/L (110 mg/dl) | Not clearly stated | 7 |
| Chen | 2018 | China | cross-sectional | 9898 | 4117 / 5781 | ≥90cm in men, ≥80cm in women or BMI ≥ 30 kg/m2 | ≥ 1.7 mmol/L or treatment for dyslipidaemia | < 1.03 mmol/L in men or <1.29mmol/L in women or treatment for dyslipidaemia | SBP ≥ 130 or DBP ≥ 85 mmHg or treatment of hypertension | FPG ≥ 5.6 mmol/ L or a history of type 2 diabetes. | thyroid ultrasonography: nodule ≥2mm in diameter. | 8 |
| Ding | 2017 | China | cross-sectional | 6365 | 3070 / 3295 | ≥ 90 cm in men, ≥ 80 cm in women | ≥1.7 mmol/L | < 1.03mmo/L in men, < 1.29 mmol/L in women | SBP ≥ 130 mmHg or DBP ≥ 85 mmHg or have been diagnosed as HBP | FPG ≥ 5.6 mmol/L or have been diagosed as type 2 diabetes | a discrete lesion within the thyroid gland that is radiologically distinct from the surrounding thyroid parenchyma | 8 |
| Feng | 2017 | China | cross-sectional | 6495 | 2427 / 4067 | ≥90cm in men, ≥80cm in women | ≥1.70 mmol/L (150 mg/dL) or specific treatment for this lipid abnormality | <1.03mmol/L (40 mg/dL) in men or <1.29 mmol/L (50 mg/dL) in women or specific treatment for this lipid abnormality | ≥130/85mmHg and/or use of anti-hypertensive medications | FPG ≥5.6mmol/L (100 mg/dL) and/or previously diagnosed type 2 diabetes. | Not clearly stated | 7 |
| Guo | 2019 | China | cross-sectional | 2606 | 1338 / 1268 | ≥90 cm in men, ≥80 cm in women | > 1.7 mmol/L (150 mg/dl) or previous lipid abnormalities, which were described as hypertriglyceridemia | < 1.03 mmol/l (40 mg/dL) in men and < 1.29 mmol/l (50 mg/dL) in women, which were described as low HDL | >130/85 mmHg or previous hypertension diagnosis, which were described as raised blood pressure | >5.6 mmol/l (100 mg/L) or previous type 2 diabetes diagnosis, which were described as dysglycemia. | ultrasound structural focal abnormalities: any area that had a different echogenicity compared to thyroid parenchyma | 6 |
| Lai | 2020 | China | retrospectively | 309576 | —— | BMI ≥25 kg/m2 | ≥1.7 mmol/L | < 0.9 mmol/ L in male, <1.0 mmol/L in female | SBP≥140 mmHg and/or DBP≥90 mmHg, and/or those who have been confirmed as hypertension and treated | FPG ≥ 6.1 mmol/L and/or PPG ≥7.8 mmol/L | thyroid nodule diagnostic guidelines issued by the American Thyroid Association in 2009 | 8 |
| Li | 2019 | China | retrospectively | 2068 | —— | BMI≥25kg/m | ≥1.7mmol/L | <0.9mmol/L in men, <1.0 mmol/L in women | ≥140/90 mmHg and/or medication | ≥ 6.1 mmol/L and/or medication | any nodular lesion that is different from the normal parenchyma of the thyroid gland based on ultrasound | 7 |
| Liang | 2020 | China | prospective | 4749 | 2525 / 2224 | ≥90 cm in men, ≥80 cm in women | >1.7mmol/L | <1.04mmol/L in men, <1.30mmol/L in female | >130/85mmHg | FPG≥5.6mmol/L | thyroid nodule with diameters equal to or exceeding 2 mm | 7 |
| Mayers | 2019 | Peru | case–control | 182 | —— | ≥90 cm in men, ≥80 cm in women | ≥1.7mmol/L (150 mg/dL) | < 1.03 mmol/l (40 mg/dL) in men and < 1.29 mmol/l (50 mg/dL) in women | SBP ≥130 mmHg or DBP ≥85 mmHg | ≥ 6.1 mmol/L (110 mg/dL) | all lesions of focal increase of volume or consistency located within the thyroid | 8 |
| Moon | 2018 | Korea | cross-sectional | 63259 | —— | ≥90cm in men, ≥80cm in women | ≥ 1.7 mmol/L (150 mg/dL) or receiving drug therapy for hypertriglyceridemia | < 1.03mmol/L (40 mg/dL) in men or < 1.29 mmol/L (50 mg/dL) in women or receiving drug therapy for reduced HDL-C | ≥ 130/85 mmHg or receiving drug therapy for hypertension | FPG ≥ 5.6 mmol/L (100 mg/dL) or receiving drug therapy for hyperglycemia | one or more discrete lesions that were within the thyroid gland but were radiologically distinct from the surrounding thyroid parenchyma | 8 |
| Pan | 2020 | China | cross-sectional | 2040 | —— | BMI ≥ 25 | ≥ 1.7mmol/L or previous TG abnormalities, described as hypertriglyceridemia | <0.9 mmol/L in men and 1.0 mmol/L in women, described as low HDL-C. | ≥ 140/90 mmHg or previously diagnosed with hypertension, described as hypertension | ≥ 6.1mmol/L or previously diagnosed with type 2 diabetes, described as hyperglycemia | a lesion within the thyroid gland that has an echoic distinction from the sur- rounding thyroid parenchyma | 7 |
| Rendina | 2012 | Italy | case–control | 1422 | —— | >102 cm in men, >88 cm in wemen | ≥1.7 mmol/L (150 mg/dl) or current drug treatment for hypertriglyceridemia | <1.03 mmol/L (<40 mg/dl) in men and <1.3 mmol/L (50 mg/dl) in women or drug treatment for low HDL-cholesterol | SBP ≥130 mmHg, DBP ≥85 mmHg or current antihypertensive drug treatment in a patient with a history of hypertension | FPG ≥5.6 mmol/l (≥100 mg/dl) or drug treatment for elevated blood glucose. | Not clearly stated | 7 |
| Shin | 2016 | Korea | case–control | 1990 | —— | ≥ 90 cm in men, ≥ 80 cm in women | ≥1.7 mmol/l (150 mg/dl) | <1.03 mmol/L (<40 mg/dl) in men and <1.3 mmol/L (50 mg/dl) in women | ≥ 130/85 mmHg or taking antihypertensive medication | FPG ≥5.6 mmol/l (≥100 mg/dl) | discrete lesions distinct from the surrounding thyroid parenchyma, and which had a solid portion regardless of the presence of a cystic portion | 8 |
| Su | 2019 | China | retrospectively | 927 | 365 / 562 | ≥90cm in men, ≥80cm in women | >1.7 mmol/L, or specific treatment for these lipid abnormalities | <1.03 mmol/L (40 mg/dL) in men and 1.29mmol/L (50mg/dL) in women | SBP >130mmHg and/or DBP >85mmHg | FPG > 5.6 mmol / L | discrete lesions, as they cause distortion of the homogeneous echo pattern of the thyroid gland | 8 |
| Our new data (TIDE) | 2021 | China | cross-sectional | 56729 | 29569 / 27160 | ≥90 cm in men, ≥85 cm in women | ≥1.7 mmol/L | < 1.0 mmol/L in men, <1.3 mmol/L in women | SBP ≥ 130 mmHg or DBP ≥ 85 mmHg or taking antihypertensive medications | FPG ≥ 5.6 mmol/L or PPG ≥ 7.8 mmol/L or HbAIc ≥ 5.7% or self-reported diabetes history or taking hypoglucemia drugs | goiter with nodules exceeding 5mm in diameter | 9 |
WC, waist circumference; TG, hypertriglyceridemia; HDL-C, high density lipoprotein cholesterol; SBP, systolic blood pressure; DBP, diastolic blood pressure; FPG, fasting plasma glucose; PPG, 2h postprandial blood glucose.