Low-density lipoproteins

Low-density lipoprotein (often abbreviated as LDL) is a fundamental component of lipid metabolism and cardiovascular health. Colloquially termed as the "bad" cholesterol, LDL plays a pivotal role in cholesterol transport and deposition in arteries, potentially leading to medical conditions such as atherosclerosis.

Structure of LDLR Family

Introduction to LDL

Atheroma

LDL is primarily tasked with transporting cholesterol from the liver to peripheral tissues. Its elevated levels, however, can result in cholesterol buildup within arterial walls, making it a significant contributor to cardiovascular diseases.

• Optimal Levels: For the majority, an LDL concentration below 100 mg/dL is deemed optimal. However, individuals with augmented risk factors like type 2 diabetes should aim for even lower levels, ideally around 75 mg/dL or below.

Significance of LDL

LDL cholesterol has gained its reputation due to its demonstrable association with heart disease:

Numerous studies have pinpointed a robust correlation between elevated LDL levels and an increased likelihood of developing heart diseases. This critical understanding underscores the imperative of maintaining LDL within healthy ranges.

Understanding Cholesterol Metabolism

A grasp of cholesterol's origin and metabolism is crucial to contextualize LDL's role:

• Endogenous production: Contrary to popular belief, dietary intake isn't the primary source of cholesterol in the body. Remarkably, the liver autonomously generates up to 70% of the body's cholesterol. This endogenous production utilizes an enzyme named HMG-CoA reductase, drawing substrates from the Kreb's cycle. The driving force behind this enzymatic activity is insulin.
• Insulin resistance: In individuals exhibiting insulin resistance, the liver, under the influence of elevated insulin levels, may overproduce cholesterol—even when dietary cholesterol is limited.
• Historically, a miscomprehension of these processes led to misguided dietary guidelines:
• The erstwhile food pyramid mistakenly posited dietary sources as the predominant contributors to cholesterol. This misconception fostered a diet low in fats and cholesterol, inadvertently promoting insulin resistance. The fallout from this misguided approach manifested in escalating obesity rates, a surge in metabolic syndrome incidence, and a staggering 500% uptick in type 2 diabetes cases.

Factors Influencing Cholesterol Levels

While the liver's endogenous cholesterol production is pivotal, external factors also modulate cholesterol levels:

• Dietary components: Saturated fats and dietary cholesterol can elevate LDL levels, although their impact may be less than historically believed.
• Body weight: Obesity or excessive body weight can skew cholesterol profiles, typically pushing LDL concentrations higher.
• Physical inactivity: Sedentariness exacerbates cardiovascular risk factors. Regular physical activity is documented to lower LDL levels and concurrently elevate HDL ("good") cholesterol.

Also see

• High-density lipoprotein
• Triglycerides
• Metabolic syndrome
• Insulin resistance
• Catechin
• Lysosomal acid lipase deficiency
• Cholesteryl ester storage disease
• Coenzyme Q10
• Flavonoid
• Glutathione
• Health effects of tea
• High density lipoprotein
• LDL receptor
• Lipid profile
• Lipoprotein(a)
• Lipoprotein-X
• Melatonin
• Saturated fat
• Sterol ester
• Vitamin A
• Vitamin C
• Vitamin E

Low-density lipoproteins Resources
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