Cholesterol normal serum levels

Standard lipid screening to obtain a cholesterol profile for the risk of cardiovascular disease routinely reports total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. Cholesterol values are reported in milligrams per deciliter of blood (mg/dL). Different organizations have made recommendations for normal cholesterol levels, but these must be interpreted carefully, as they are contingent on other risk conditions. For example, the recommendations for smokers or those with a family history of heart disease will be lower for someone without these conditions. The National Center for Cholesterol Education (NCEP) endorsed by the American Heart Association believes that LDL is the primary cholesterol component to determine therapy. LDL cholesterol accounts for 60—70% of blood serum cholesterol. An LDL less than 160 mg/dL is recommended for individuals with no more than one risk factor and less than 100 mg/dL for individuals with coronary heart disease. NCEP classifies HDL, which comprises between 20% and 30% of blood cholesterol, below 40 mg/dL as low. Triglycerides are an indirect measure of VLDL cholesterol. The NCEP considers a normal triglyceride level as less than 150 mg/dL. 

Recessive X-linked ichthyosis (RXLI) is a dermatological condition that is caused by steroid sulfatase deficiency (STSD), although the mechanism by which the deficiency causes the characteristic scaly skin has not been adequately explained. RXLI is the most common genetic disorder of steroid metabolism, affecting about 1 2000 males. Epstein and workers [16] first demonstrated that serum cholesterol sulfate was elevated in the condition, and this compound has become the preferred analyte for diagnosis. The serum level is more than tenfold greater than normal in the condition. 

Hyperlipidemia (mainly hypercholesterolemia) is a regular part of nephrotic syndrome (K13, W6). Serum levels of cholesterol are often markedly elevated, usually above 10 mmol/L. However, in severely malnourished patients, normal or even decreased serum cholesterol level can be found. Serum levels of triacylglyc-erols fluctuate, from normal values to markedly elevated values (mainly in patients with proteinuria higher than 10 g/24 hr). There is a variable increase in plasma concentrations of very low density lipoproteins (VLDL, they correlate negatively with serum albumin level), intermediate-density lipoproteins (IDL), andLDL however, plasma concentrations of HDL are usually normal (J3). Levels of lipoprotein(a) [Lp(a)j are also increased (W4). Remission of nephrotic syndrome or decrease of proteinuria may result in the decrease of plasma concentrations of Lp(a) (G2). Concentration of free fatty acids in serum is commonly decreased because they are normally bound to albumin and albumin is lost into the urine. The activity of lecithin cholesterol acyltransferase (LCAT) is usually decreased. 

Braunwald (1997) points out that fully half of all patients with CHD do not have any of the conventional risk factors (hypertension, hypercholesterolemia, cigarette smoking, diabetes mellitus, marked obesity and physical inactivity). Further, up to two-thirds of patients with CHD have what may be considered normal serum cholesterol levels (see references in Parodi, 2004). These facts suggest that the role of plasma cholesterol in CHD has been overemphasized and oversimplified. 

Elevated LDL with normal VLDL levels due to block in LDL degradation, therefore increased serum cholesterol but normal triacylglycerol. 

Although there are still some discrepancies in the hterature regarding zinc levels in dialysis patients, most studies have found decreased levels of the element in serum [64,65] and muscles whereas the levels in bone [63] and other tissues seem to be normal or even increased suggesting translocation of the element in uremia. The dialysis treatment itself seems to have little or no effect on the serum zinc concentrations. Zinc deficiency in uremic patients has been associated with anorexia, disturbances in taste and sexual performance [66] whereas decreased plasma zinc seem to correlate with erythrocyte superoxide dismutase levels [67]. As evaluated by Tiirk et al. [68], zinc supplementation did not have any effect on the restoration of immune parameters or enhancement of the antibody response to multivalent influenza vaccine in hemodialysis patients. On the ofher hand however, has zinc supplementation been reported an effective means of improving serum levels of zinc and cholesterol in the hemodialysis patient [69]. 

Initially recorded with rare paraproteins (B23), mainly of the IgA class, this has also been associated with IgG and IgM. Usually the total serum cholesterol is raised, but in one case it has been within normal limits curiously it is subnormal in most patients with IgA-myelomatosis without xanthoma (S7). The xanthomata are typically of the soft eruptive variety and contain complexes of the paraprotein and /8-Iipo-protein. Beaumont (B8) has collected evidence suggesting that the paraproteins are antibodies to the 8-apoprotein. Occasionally excess complexes can result in viscosity syndrome (Section 7.5.6). If a lipid stain is used, the paraprotein band is positive. In such cases, regrettably. Potter has been unable to relate the antibody activity to phosphoryl-choline (P13). Cytotoxic treatment can reduce the serum levels of lipid and paraprotein. 

Ann Jeina is typical of patients with essentially normal serum triacyl-j glycerol levels and elevated serum total cholesterol levels that are repeat-... 

TSH levels are increased (overt hypothyroidism). Some authors reported that individuals with TSH values in the upper half of the reference range had a higher mean serum cholesterol level than those with low-normal TSH levels (Michalopoulou et al., 1998). Accordingly, some authorities (National Academy of Clinical Biochemistry) have proposed to lower the upper limit for TSH levels to 2.5mU/l (Baloch et ai, 2003 Wartofsky and Dickey, 2005). This criterion has been criticized because it would result in an overdiagnosis of subciinicai hypothyroidism and an increase in the number of patients on unnecessary replacement therapy (Surks et al., 2005 Dlez et al., 2005). 

At her annual medical checkup. It was noted that MK s total serum cholesterol and LDL levels were mildly elevated, although her triglycerides and HDL levels were hovering around normal. Given her cardiovascular history, the physician wishes to Implement therapy to bring her blood lipids down to National Cholesterol Education Program (NCEP)-recommended levels. 

In hypophysectomized rats, the synthesis of cholesterol from acetate (19,20)—but not from mevalonate (21)—is inhibited, indicating that pituitary hormones have an effect on a metabolic step between acetate and mevalonate, probably on hydroxymethylglutaryl-coenzyme A reductase. In terms of tissue cholesterol concentrations, the hypophysectomized rat differs little from the normal. Although bile acid synthesis and excretion are reduced, these animals reach a steady state in which normal cholesterol concentrations in plasma and tissue are maintained (21,22). This is true, however, only when the hypophysectomized rat is maintained on a low-cholesterol diet. When cholesterol intake is increased, both serum and tissue cholesterol reach high levels, presumably because of the decreased ability of the hypophysectomized rat to eliminate that sterol by conversion to bile acids (10, 11,23). 

Numerous researchers have drawn attention to the beneficial properties that avocado could provide to human health. Some of these healthy benehts have been summarized in Figure 8.1. Wilson Grant, in 1960, published the hrst clinical study where avocado intake was associated with the maintenance of normal serum cholesterol levels, or even with their reduction [7]. Later on, in the 90s and beginning of 2000 there was an increase in the number of works that studied the relationship between avocado fat and its effect on cardiovascular diseases, cholesterol, lipid profile, weight control, and diabetes [8-16]. While the principal healthy benehts attributed to avocado fruit are the aforementioned, some others have also been evaluated, such as prevention and treatment of osteoarthritis [17,18], anticancer properties [19-24], protective activity against liver injury [25], skin protection [26-28], reduction of risk of macular degeneration [29], inhuence on short-term memory [30], antioxidant activity [31-37], reduction of metabolic syndrome risk [38,39], and anti-inhammatory effects [31,32,40]. 

Katz etal. (1980) first reported elevations of triglycerides and reduced level of high-density lipoproteins (HDL) in seven of ten patients with disorders of keratinization treated with isotretinoin however, normal serum cholesterol levels were maintained. Elevations of serum triglycerides were seen at doses > 1.0 mg/... 

Normal /8-lipoprotein levels were found in other heterozygotes (Ways et al. 1963). Forsyth et al. (1965) even reported elevation of Sf 3—9 /8-lipoproteins, of total lipids and cholesterol in both parents, in the maternal grandmother, and in two siblings of the mother of his case, a-lipoproteins tended to be low. One sibling of the mother and a sister of the father had normal serum lipid levels. 

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