le triacylglycerol (TAG) (-51%), HDL-C (13%) and total cholesterol/HDL-C ratio (-14%) responses. In addition to these markers for MetS, the CRD subjects showed more favorable responses to alternative indicators of cardiovascular risk: postprandial lipemia (-47%), the Apo B/Apo A-1 ratio (-16%), and LDL particle distribution. Despite a threefold higher intake of dietary saturated fat during the CRD, saturated fatty acids in TAG and cholesteryl ester were significantly decreased, as was palmitoleic acid (16:1n-7), an endogenous marker of lipogenesis, compared to subjects consuming the LFD. Serum retinol binding protein 4 has been linked to insulin-resistant states, and only the CRD decreased this marker (-20%). The findings provide support for unifying the disparate markers of MetS and for the proposed intimate connection with dietary carbohydrate. The results support the use of dietary carbohydrate restriction as an effective approach to improve features of MetS and cardiovascular risk.
32 Evidence type: randomized controlled trial
Effect of a low-carbohydrate, ketogenic diet program compared to a low-fat diet on fasting lipoprotein subclasses. Westman EC, Yancy WS Jr, Olsen MK, Dudley T, Guyton JR. Int J Cardiol. 2006 Jun 16;110(2):212-6. Epub 2005 Nov 16.
Comparing baseline to 6 months, the LCKD [low carb ketogenic diet] group had significant changes in large VLDL (-78%), medium VLDL (-60%), small VLDL (-57%), LDL particle size (+2%), large LDL (+54%), medium LDL (-42%), small LDL (-78%), HDL particle size (+5%), large HDL (+21%), and LDL particle concentration (-11%).
CONCLUSIONS: The LCKD with nutritional supplementation led to beneficial changes in serum lipid subclasses during weight loss. While the LCKD did not lower total LDL cholesterol, it did result in a shift from small, dense LDL to large, buoyant LDL, which could lower cardiovascular disease risk.
33 Evidence type: longitudinal analysis
Change in LDL particle size is associated with change in plasma triglyceride concentration. McNamara JR, Jenner JL, Li Z, Wilson PW, Schaefer EJ. Arterioscler Thromb. 1992 Nov;12(11):1284-90.
Low density lipoprotein (LDL) particle size is inversely associated with plasma triglyceride concentration in cross-sectional analyses. In the present study, changes in the LDL particle size of 227 participants of the Framingham Offspring Study were analyzed longitudinally by nondenaturing gradient gel electrophoresis at two examinations that were separated by 3-4 years. All subjects had triglyceride concentrations < 400 mg/dl at both exams. Using laser scanning densitometry to assess mean LDL particle size, 56% of samples displayed a change in size: 41% had a one-band size change, 13% had a two-band change, and 2% had a three-band change. These changes in size corresponded to a 15% change in pattern type, based on pattern A and B terminology. There was a significant inverse association between change in LDL size and change in triglyceride (p < 0.0001) and glucose (p < 0.004) concentrations, body weight (p < 0.02), and age (p < 0.03). There was also a significant positive association with change in high density lipoprotein (HDL) cholesterol concentration (p < 0.0001).
34 Evidence type: observational
Ratio of triglycerides to HDL cholesterol is an indicator of LDL particle size in patients with type 2 diabetes and normal HDL cholesterol levels. Boizel R, Benhamou PY, Lardy B, Laporte F, Foulon T, Halimi S. Diabetes Care. 2000 Nov;23(11):1679-85.
LDL size correlated negatively with plasma triglycerides (TGs) (R2 = 0.52) and positively with HDL cholesterol (R2 = 0.14). However, an inverse correlation between the TG-to-HDL cholesterol molar ratio and LDL size was even stronger (R2 = 0.59). The ratio was > 1.33 in 90% of the patients with small LDL particles (95% CI 79.3-100) and 16.5% of those with larger LDL particles. A cutoff point of 1.33 for the TG-to-HDL cholesterol ratio distinguishes between patients having small LDL values better than TG cutoff of 1.70 and 1.45 mmol/l.
CONCLUSIONS: The TG-to-HDL cholesterol ratio may be related to t