Which statement regarding statins is correct?

Statins are a class of medications primarily known for their ability to lower LDL cholesterol levels, which is often referred to as "bad" cholesterol. They achieve this by inhibiting the enzyme HMG-CoA reductase in the liver, which plays a central role in the cholesterol biosynthesis pathway. By reducing the liver's production of cholesterol, statins lead to a decrease in serum LDL cholesterol levels, thereby helping to prevent cardiovascular disease, including heart attacks and strokes.

The other statements do not accurately reflect the established roles and effects of statins. For instance, statins are not designed to lower blood pressure; that function is typically addressed by other classes of antihypertensive medications. While some studies suggest statins might have a favorable impact on insulin sensitivity, this is not their primary indication or a consistent finding among all patients. Lastly, statins are effective across a wide age spectrum, not just for young adults, as they are commonly prescribed to older adults and those with various risk factors for elevated cholesterol levels and cardiovascular disease.