UBCLINICAL OR "MILD" THYROID disease is a common disorder, particularly in middle-aged and elderly individuals. 1 Greater sensitivity of assays and more frequent assessment of serum thyroidstimulating hormone (TSH) levels have resulted in more patients requiring interpretation of abnormal thyroid function test results. However, controversy surrounds the definition, clinical importance, and necessity for prompt diagnosis and treatment of subclinical thyroid disease. Previous review articles 2-6 and position statements 7,8 differ in their conclusions and recommendations, often a consequence of difficulties in interpreting inadequate and conflicting data. In the midst of this uncertainty, clinicians still desire expert guidance for the diagnosis and management of subclinical thyroid disease.

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Young adult survivors of childhood ALL, especially those treated with CRT, are at risk for obesity and dyslipidemia, insulin resistance, hypertension, and cardiovascular disease. Further investigation of these risks is warranted.

Excess body weight is associated with deleterious changes in the lipoprotein profile. Higher BMI was associated at all ages with higher plasma triglyceride level, lower HDL cholesterol level, and higher total and non-HDL cholesterol levels. In young men, the higher total cholesterol level was reflected mainly in the LDL cholesterol level; in middle-aged and older men, in the non-HDL fraction. Programs to reduce coronary heart disease by improving lipid levels should include more emphasis on achieving and maintaining ideal body weight.

The effects of lauric acid (C12:0) on plasma lipids and lipoproteins were compared with the effects of palmitic acid (C16:0) and oleic acid (C18:1) in a metabolic-diet study of 14 men by using liquid-formula diets fed for 3 wk each in random order. Lauric acid was supplied in a synthetic high-lauric oil, palmitic acid was provided by palm oil and oleic acid in oleic-rich sunflower seed oil. The high-lauric oil resulted in higher concentrations of plasma total cholesterol (4.94 +/- 0.75 mmol/L [mean +/- SE]) and LDL cholesterol (3.70 +/- 0.57 mmol/L) when compared with high-oleic sunflower oil (4.44 +/- 0.54 and 3.31 +/- 0.44 mmol/L, respectively), but did not raise total and LDL cholesterol concentrations as much as did palm oil (5.17 +/- 0.65 and 3.93 +/- 0.51 mmol/L, respectively). No differences were noted in plasma triglycerides or HDL cholesterol. Lauric acid raises total and LDL cholesterol concentrations compared with oleic acid, but is not as potent for increasing cholesterol concentrations as is palmitic acid.

For young women, excess body weight was associated with higher total, non-HDL and LDL-cholesterol levels, higher triglyceride levels, and lower HDL-cholesterol levels. In older women, although similar differences in triglyceride levels and HDL-cholesterol levels were observed, excess body weight was associated with smaller differences in total, non-HDL, and LDL cholesterol. More striking than the weight-associated differences in total, non-HDL, and LDL-cholesterol levels were the differences in these lipid parameters observed with age alone. Specifically, age category differences were twofold to eightfold greater than differences observed between categories of BMI within a given age. Nevertheless, because the lower HDL cholesterol concentrations associated with excess body weight were age independent, total cholesterol-HDL cholesterol ratios were highest in obese postmenopausal women. Although age and hormonal status are important affecters of lipoprotein risk factors, body weight also worsens the degree of dyslipidemia in white women.

Plasma cholesteryl esters, synthesized in the high density lipoproteins (HDL), may be transferred to other lipoproteins by a cholesteryl ester transfer protein (CETP). We found a twofold increase in mass transfer of cholesteryl ester from HDL to apoBcontaining lipoproteins in incubated hypercholesterolemic rabbit plasma compared with control. There was a two-to fourfold increase in the activity of CETP, measured in an isotopic assay in hypercholesterolemic plasma. A CETP-like molecule was isolated in increased amounts from hypercholesterolemic plasma. Incubated plasma from four dysbetalipoproteinemic subjects also showed an increase (threefold) in cholesteryl ester mass transfer, compared with normolipidemic controls. There was a twofold increase in the activity of CETP, assayed in whole or lipoproteinfree plasma. Thus, there is increased transfer of cholesteryl esters from HDL to potentially atherogenic apoB-containing lipoproteins in dyslipidemic rabbit and human plasma. The enhanced transfer results in part from increased activity of CETP, possibly reflecting an increase in CETP mass.

Although medium-chain triacylglycerols (MCTs, composed of medium-chain fatty acids 8:0 and 10:0) have long been described as having neutral effects on serum cholesterol concentrations, experimental evidence supporting this claim is limited. In a randomized, crossover, metabolic-ward study, we compared the lipid effects of a natural food diet supplemented with either MCTs, palm oil, or high oleic acid sunflower oil in nine middle-aged men with mild hypercholesterolemia. Rather than having a neutral effect, MCT oil produced total cholesterol concentrations that were not significantly different from those produced by palm oil (MCT oil: 5.87 +/- 0.75 mmol/L; palm oil: 5.79 +/- 0.72 mmol/L) but significantly higher than that produced by high oleic acid sunflower oil (5.22 +/- 0.52 mmol/L). Low-density-lipoprotein (LDL)-cholesterol concentrations paralleled those of total cholesterol. MCT oil tended to result in higher triacylglycerol concentrations than either palm oil or high oleic acid sunflower oil, but this difference was not significant. There were no differences in high-density-lipoprotein cholesterol concentrations. The palmitic acid and total saturated fatty acid content of plasma triacylglycerols in the MCT-oil diet was not significantly different from that in the palm oil diet. On the basis of percentage of energy, this study suggests that medium-chain fatty acids have one-half the potency that palmitic acid has at raising total and LDL-cholesterol concentrations.