There are no standardized variables defined for calculating factor scores using PCA. Most researchers used four factors with HOMA or insulin instead of glucose, triglycerides to HDL ratio are also calculated to reduce number of factors, and blood pressure is calculated either using systolic blood pressure or MAP. Confirmatory analyses in these studies revealed higher factor loadings of waist circumference and glucoregulation measures than loadings of blood pressure and lipids [22, 26 ].
Source: wiktionary