Strong association between cardiorespiratory fitness and serum lipoprotein subclass pattern in prepubertal healthy children.

This study reveals the lipoprotein subclass pattern associated with cardiorespiratory fitness (CRF) in healthy children. Serum concentrations of lipoprotein subclasses and concentrations and average particle size of their main classes were quantified in 94 ethnic Norwegian children using high-performance liquid chromatography (HPLC). Twenty-four lipoprotein features were used as input to multivariate regression analysis with CRF measured either by peak oxygen consumption (VO2peak) using a continuous treadmill protocol or indirectly by the 10-minute Andersen intermittent running field test. By including BMI and gender as descriptors, a predictive cross-validated multivariate regression model was obtained for both CRF measures. CRF correlated positively with average particle size for high-density lipoprotein (HDL) and its subclasses of large HDL particles and negatively with very small HDL particles, chylomicrons, triglycerides, and average size and concentration of very low-density lipoprotein (VLDL) particles and VLDL subclasses of large particles (P<.05). BMI correlated negatively with both measures of CRF, but exhibited a stronger association with VO2peak than with the Andersen test. Our data showed a strong association between CRF measured either by VO2peak or by the Andersen test and a subclass lipoprotein pattern that is associated with cardiovascular (CV) health. Thus, our results show why high levels of CRF are beneficial for children's CV health. The Andersen test, being a practical field test that involves minimal equipment and, being less influenced by BMI than VO2peak, represents a good measure of CRF, and, accordingly, a proxy measure of cardiovascular health status in children.

Intensive lifestyle intervention provides rapid reduction of serum fatty acid levels in women with severe obesity without lowering omega-3 to unhealthy levels.

Serum fatty acid (FA) levels were monitored in women with severe obesity during intensive lifestyle intervention. At baseline, total FA levels and most individual FAs were elevated compared to a matching cohort of normal and overweight women (healthy controls). After 3 weeks of intensive lifestyle intervention, total level was only 11-12% higher than in the healthy controls and with almost all FAs being significantly lower than at baseline, but with levels of omega-3 being similar to the healthy controls. This is contrary to observations for patients subjected to bariatric surgery where omega-3 levels dropped to levels significantly lower than in the lifestyle patients and healthy controls. During the next 3 weeks of treatment, the FA levels in lifestyle patients were unchanged, while the weight loss continued at almost the same rate as in the first 3 weeks. Multivariate analysis revealed that weight loss and change of serum FA patterns were unrelated outcomes of the intervention for lifestyle patients. For bariatric patients, these processes were associated probably due to reduced dietary input and increased input from the patients' own fat deposits, causing a higher rate of weight loss and simultaneous reduction of the ratio of serum eicosapentaenoic to arachidonic acid.

Impact of physical activity and diet on lipoprotein particle concentrations in severely obese women participating in a 1-year lifestyle intervention.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Physical activity and high aerobic fitness protects against cardiovascular disease and early death, besides having a very modest impact on lipoprotein-cholesterol in obese subjects. Physical activity has been shown to favourably alter lipoprotein particle concentrations and apolipoprotein B with minimal weight loss in overweight to moderately obese subjects. WHAT THIS STUDY ADDS: We studied the impact of physical activity on lipoprotein subclass particle concentrations in women with severe obesity. Increased physical activity duration was associated with favourable changes, whereas increased PA intensity was associated with adverse changes in some lipoprotein particle subclasses in severely obese women. Severely obese women that manage to increase their physical activity level can improve their lipoprotein profile, whether or not they lose fat mass Physical activity (PA) and high aerobic fitness protects against cardiovascular disease and early death possibly among others because of an anti-atherogenic impact on lipoprotein particle concentrations. The objective of this study was to determine the impact of PA and diet on lipoprotein particle concentrations. Thirty-one severely obese women (age 43.6 ± 10.2 years; body mass index 43.0 ± 6.3 kg m(-2) ) participated in a 1-year lifestyle intervention with repeated measurements of lipoprotein particle subclass concentrations and size of very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL), as well as fat mass, PA and diet. Multiple regression was used to determine associations with change (Δ) in two principal components (PCs) describing lipoprotein distributions: ΔPC 1 LIPO (dominated by VLDL and LDL) and ΔPC 2 LIPO (dominated by large HDL and mean HDL particle size). ΔPA duration was the only variable that was significantly related to ΔPC 1 LIPO (partial r = -0.40, P = 0.008), while ΔPA intensity was the only variable that was significantly related to ΔPC 2 LIPO (partial r = -0.43, P = 0.003) in adjusted models. Increased PA duration was associated with favourable changes, whereas increased PA intensity was associated with adverse changes in some lipoprotein particle subclasses in severely obese women.

Resolution of two-way data: theoretical background and practical problem-solving. Part 1: theoretical background and methodology.

This paper reviews recent progress in the resolution of two-way data obtained from hyphenated instruments. Special emphasis is placed on the solution of practical problems. Methods for estimating the number of chemical components both statistically and visually (the first step in solving the resolution problem) and methods for resolving the pure profiles (the second step in solving the resolution problem) are discussed in detail. To deal with real-world problems, pitfalls in the chemometric analysis of the two-way data from the instrumental measurements are also pointed out. Applications of methods for solving some difficult practical problems in environmental chemistry, pharmaceutical chemistry, and physical chemistry will be discussed in the second part of this paper.

Reaction of aluminium chloride with poly(divinyl benzene) particles--a reaction kinetic study using infrared spectroscopy.

Porous poly(para-divinylbenzene) and poly(meta-divinylbenzene) particles were synthesised from para-divinylbenzene and meta-divinylbenzene monomers with toluene and 2-ethylhexanoic acid as porogens. The residual vinyl groups in the particles were thereafter reacted using aluminium chloride with dichlorobenzene as a catalyst. The conversion of vinyl groups was followed by analysing polymer particles taken from the reaction mixture at different time intervals. Infrared spectroscopy both in the mid and near infrared region was used as the analytical technique. The intensity changes in the overtone absorption at 1628 nm due to the vinyl bonds were used as the basis for the quantification of the vinyl group consumption. Infrared spectra of the particles in the mid IR were also measured to understand changes taking place in the polymer matrix during the reaction. The results indicated that residual vinyl groups in these polymer particles were consumed during the reaction with aluminium chloride. The reaction of aluminium chloride with the polymer matrix was explained by proposing mechanisms for the formation of different products during the reaction. The complex formed between aluminium chloride and the residual vinyl groups seemed to induce addition of HCl to the vinyl group or leads to crosslinking and/or cyclisation in the case poly(para-DVB) particles. The reaction of aluminium chloride with poly(meta-DVB) takes place to a lesser extent.

Proton nuclear magnetic resonance spectroscopy of serum from patients with colorectal neoplasia.

Proton nuclear magnetic resonance (NMR) spectra of serum have been recorded from patients with colorectal neoplastic polyps, before and after treatment of colorectal cancer, in patients with advanced lung cancer, and also from healthy controls. Digitally defined NMR profiles of the methyl and methylene peaks were used as input for supervised principal component modelling. An unknown sample was classified according to its residual, i.e. the difference between the spectral pattern of the unknown and control group. There was a statistically significant difference between the mean residual in the untreated colorectal cancer group and in controls (P = 0.003). The sensitivity of detecting untreated colorectal cancer was only 20%. There were no stage-dependent differences between the residuals within the untreated colorectal cancer group. After curative surgery, four patients had recurrence of malignant disease without an increase in residual prior to recurrence. Patients with advanced malignant disease (lung cancer WHO stage IIIB and IV) had a highly significant difference in mean residual from that of controls, with a sensitivity of detecting cancer of 87.5%. This increase in residual could not be explained by increase in the level of serum triglyceride. NMR spectroscopy was not a useful diagnostic tool in patients with colorectal neoplastic polyps and cancer.

Detection of malignant tumours by multivariate analysis of proton magnetic resonance spectra of serum.

Proton magnetic resonance spectra of blood serum have been subjected to multivariate data analysis to discriminate between samples from cancer patients and from controls. The main feature was the use of digitally defined resonance profiles. The methyl and methylene lipoprotein signals centred at 1.3 and 0.9 parts per million are non-lorentzian composite peaks that cannot be described properly by the line width at half-height. Instead 71 and 76 data points were used to describe the methylene and methyl peak profiles, respectively. These data points were used as input to a principal component analysis to distinguish between malignant (n = 29) and control samples (n = 55). At a probability level of 0.01 (F-test) modelling classified all patients except 2 correctly, while 1 control was slightly above the predictive level for malignancy.