“…Twenty-nine studies on the association between PD and serum TG level were published between 1999 and 2018, and involved a total of 4836 cases, including 2060 patients with PD and 2776 healthy participants ( Table 1). There was a variation in their geographical locations including the USA (n = 1), 6 Germany (n = 1), 7 Srbija (n = 1), 19 Austria (n = 1), 21 Colombia (n = 1), 27 Turkey (n = 2), 11,29 Brazil (n = 3), 8,13,31 Iran (n = 4), 9,15,16,23 China (n = 5) 10,12,18,20,30 and India (n = 10) 14,17,22,[24][25][26]28,[32][33][34] (Table 1). For statistical analysis, we divided one study into two or three comparison groups according to the severity of PD (light, moderate and severe).…”