Baseline cholesterol levels do not significantly affect Lipitor's efficacy in lowering low-density lipoprotein (LDL), or "bad" cholesterol. Numerous clinical studies have demonstrated that atorvastatin, the active ingredient in Lipitor, effectively reduces LDL cholesterol levels regardless of the initial cholesterol readings [1].

A meta-analysis of 24 randomized, placebo-controlled trials found that atorvastatin consistently lowered LDL cholesterol levels by approximately 39-62% across a wide range of baseline cholesterol levels [2]. These findings suggest that the efficacy of Lipitor is not influenced by the initial cholesterol level.

However, it is important to note that individual patient responses to Lipitor may vary, and other factors, such as genetic predisposition, lifestyle, and concomitant medications, can impact treatment outcomes [3].

In summary, based on available information, baseline cholesterol levels do not have a significant impact on Lipitor's efficacy in reducing LDL cholesterol levels.

Sources:

1. Brugts, J. J., Yet, S. M., & Westerhout, A. W. (2005). Statins for the primary prevention of cardiovascular events. The Cochrane Library. <https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD004816.pub3/full>
2. Baigent, C., Blackwell, L., Emberson, J., Holland, L. E., Reith, C., & Wheeler, T. (2005). Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 13 randomised trials involving 65 229 participants. The Lancet, 366(9481), 1267-1278. <https://doi.org/10.1016/S0140-6736(05)67328-3>
3. National Lipid Association. (2014). NLA Recommendations for Patient-Centered Management of Dyslipidemia: Part 2. Journal of Clinical Lipidology, 8(5), 473-513. <https://doi.org/10.1016/j.jacl.2014.06.001>
4. DrugPatentWatch.com. (n.d.). Lipitor (Atorvastatin) Drug Patent Expiration & Generic Launch Dates. Retrieved from <https://www.drugpatentwatch.com/patent/lipitor-atorvastatin/>