Non-cholesterol sterol levels predict hyperglycemia and conversion to type 2 diabetes in Finnish men.

We investigated the levels of non-cholesterol sterols as predictors for the development of hyperglycemia (an increase in the glucose area under the curve in an oral glucose tolerance test) and incident type 2 diabetes in a 5-year follow-up study of a population-based cohort of Finnish men (METSIM Study, N = 1,050) having non-cholesterol sterols measured at baseline. Additionally we determined the association of 538,265 single nucleotide polymorphisms (SNP) with non-cholesterol sterol levels in a cross-sectional cohort of non-diabetic offspring of type 2 diabetes (the Kuopio cohort of the EUGENE2 Study, N = 273). We found that in a cross-sectional METSIM Study the levels of sterols indicating cholesterol absorption were reduced as a function of increasing fasting glucose levels, whereas the levels of sterols indicating cholesterol synthesis were increased as a function of increasing 2-hour glucose levels. A cholesterol synthesis marker desmosterol significantly predicted an increase, and two absorption markers (campesterol and avenasterol) a decrease in the risk of hyperglycemia and incident type 2 diabetes in a 5-year follow-up of the METSIM cohort, mainly attributable to insulin sensitivity. A SNP of ABCG8 was associated with fasting plasma glucose levels in a cross-sectional study but did not predict hyperglycemia or incident type 2 diabetes. In conclusion, the levels of some, but not all non-cholesterol sterols are markers of the worsening of hyperglycemia and type 2 diabetes.

High intestinal cholesterol absorption is associated with cardiovascular disease and risk alleles in ABCG8 and ABO: evidence from the LURIC and YFS cohorts and from a meta-analysis.

OBJECTIVES: This study sought to determine whether high intestinal cholesterol absorption represents a cardiovascular risk factor and to link ABCG8 and ABO variants to cardiovascular disease (CVD). BACKGROUND: Plant sterol-enriched functional foods are widely used for cholesterol lowering. Their regular intake yields a 2-fold increase in circulating plant sterol levels that equally represent markers of cholesterol absorption. Variants in ABCG8 and ABO have been associated with circulating plant sterol levels and CVD, thereby suggesting atherogenic effects of plant sterols or of cholesterol uptake. METHODS: The cholestanol-to-cholesterol ratio (CR) was used as an estimate of cholesterol absorption because it is independent of plant sterols. First, we investigated the associations of 6 single nucleotide polymorphisms in ABCG8 and ABO with CR in the LURIC (LUdwisghafen RIsk and Cardiovascular health study) and the YFS (Young Finns Study) cohorts. Second, we conducted a systematic review and meta-analysis to investigate whether CR might be related to CVD. RESULTS: In LURIC, the minor alleles of rs4245791 and rs4299376 and the major alleles of rs41360247, rs6576629, and rs4953023 of the ABCG8 gene and the minor allele of rs657152 of the ABO gene were significantly associated with higher CR. Consistent results were obtained for rs4245791, rs4299376, rs6576629, and rs4953023 in YFS. The meta-analysis, including 6 studies and 4,362 individuals, found that CR was significantly increased in individuals with CVD. CONCLUSIONS: High cholesterol absorption is associated with risk alleles in ABCG8 and ABO and with CVD. Harm caused by elevated cholesterol absorption rather than by plant sterols may therefore mediate the relationships of ABCG8 and ABO variants with CVD.

Physical activity in midlife and telomere length measured in old age.

Physical activity has been associated with alterations in telomere length, a potential indicator of biological aging, but several inconsistencies exist. Our aim was to investigate the associations between physical activity in midlife and leukocyte telomere length (LTL) measured in old age in the Helsinki Businessmen Study, Finland. At entry, in 1974, 782 men (mean age 47) completed a questionnaire about their physical activity and this was collapsed into 3 categories: low (n=148), moderate (n=398) and high physical activity (n=236, 7 of whom had a competitive activity level). After 29-year follow-up in 2003, mean LTL and the proportion of short (<5 kB) telomeres were measured from DNA samples of a random subcohort of survivors (n=204, mean age 76) using the Southern blot technique. Adjusted for age, body mass index (BMI), cholesterol and smoking in 1974, the moderate physical activity group had longer mean LTL (8.27 kB, SE 0.05) than the low (8.10 kB, SE 0.07), or high (8.10 kB, SE 0.05) physical activity groups (P=0.03 between groups). Conversely, the proportion of short telomeres was lowest in the moderate physical activity group (11.35%, SE 0.25), and higher in the high (12.39%, SE 0.29), and the low physical activity (12.21%, SE 0.39) groups (P=0.02 between groups). We conclude that the results of this observational cohort study give support to the idea that both low and high physical activity is in the long-term associated with factors shortening LTL.

Parenteral plant sterols and intestinal failure-associated liver disease in neonates.

OBJECTIVES: We prospectively evaluated incidence of prolonged (>28 days) parenteral nutrition (PN), associated complications, and significance of parenteral plant sterols (PS) in neonatal intestinal failure-associated liver disease (IFALD) compared with children. METHODS: We recruited 28 neonates (mean age 50 days, range 28-126) and 11 children (6.9 y, 2.1-16.6) in all of Finland. Patients underwent repeated measurements of serum cholesterol, noncholesterol sterols, including PS, cholestanol and cholesterol precursors, and liver biochemistry during and 1 month after discontinuation of PN. Healthy matched neonates (n=10) and children (n=22) served as controls. RESULTS: IFALD occurred more frequently among neonates (63%) than children (27%; P<0.05). Ratios of serum PS, including stigmasterol, sitosterol, avenasterol, and campesterol, and total PS were increased among neonates compared with healthy controls and children on PN by 2- to 22- and 2- to 5-fold (P<0.005), respectively. Neonates with IFALD had significantly higher ratios of serum PS and cholestanol compared with neonates without IFALD (P<0.05). Total duration of PN associated with serum cholestanol, stigmasterol, avenasterol, alanine aminotransferase, and aspartate aminotransferase (r=0.472-0.636, P<0.05). Cholestanol and individual serum PS, excluding campesterol, reflected direct bilirubin (r=0.529-0.688, P<0.05). IFALD persisted after discontinuation of PN in 25% of neonates with 4.2- and 2.2-times higher ratios of serum stigmasterol and cholestanol compared with neonates without IFALD (P<0.05). CONCLUSIONS: Frequent occurrence of IFALD among neonates on PN displays an association to duration of PN and markedly increased serum PS, especially stigmasterol, in comparison to healthy neonates and children on PN. Striking accumulation of parenteral PS may contribute to IFALD among neonates.

Effect of cholesterol on mortality and quality of life up to a 46-year follow-up.

The effect of cholesterol level on the health of older people is a matter of debate, probably because of the bidirectional association. We investigated this paradox in a long-term study. The baseline assessments of the Helsinki Businessmen Study (a cohort of mainly business executives, born 1919 to 1934) included the total cholesterol value and other cardiovascular risk factors from 1964 to 1973. These men were followed up for ≤46 years (through January 2010). During the follow-up period, the cholesterol value was assessed by self-report in 2000 (n = 1,292). Mortality was ascertained from the national registers, symptoms, and health-related quality of life with RAND-36 from questionnaires in 2000. A total of 3,277 healthy men without chronic diseases at baseline were included in the analyses. The median total cholesterol concentration at baseline was 6.5 mmol/L (251 mg/dl) (interquartile range 5.8 to 7.3 mmol/L, 224 to 282 mg/dl) and, in 2000, was 5.2 mmol/L (201 mg/dl) (interquartile range 4.6 to 5.9 mmol/L, 178 to 228 mg/dl). During the follow-up period, 1,773 men (54%) died. A strong and graded relation was found between the cholesterol level and total mortality, with the men with a cholesterol level ≤4 mmol/L (154 mg/dl) having the lowest mortality. In all, the men with the lowest cholesterol gained the most life years. However, no association was found with the cholesterol level in 2000 (when 16% were using statins) and subsequent mortality. The lowest (≤4 mmol/L) cholesterol value in midlife also predicted a higher score in the physical functioning scale of RAND-36 in old age. In conclusion, a low total cholesterol value in midlife predicts both better survival and better physical functioning in old age.

Association of telomere length in older men with mortality and midlife body mass index and smoking.

BACKGROUND: Leukocyte telomere length has been taken as a measure of biological age but several inconsistencies exist. METHODS: We investigated associations between leukocyte telomere length in old age, midlife risk factors, and mortality. The Helsinki Businessmen Study (a cohort of mainly business executives, born 1919-1934) had baseline assessments of cardiovascular risk factors including body mass index between 1964 and 1973 at a mean age of 40. Leukocyte telomere length and proportion of short telomeres were measured from DNA samples collected in 2002-2003 (n = 622, mean age 78 years). Body mass index and smoking in old age were assessed from questionnaires. Total mortality was verified from registers through January 2010. Main outcome measures were relationships between telomeres, body mass index, smoking, and mortality. RESULTS: Leukocyte telomere length and notably proportion of short telomeres (<5kb) in old age were significantly (p =. 008 after full adjustments) and in a graded manner associated with midlife overweight and smoking. The associations were independent of age and cardiovascular risk factors including postload glucose. Associations with body mass index and smoking were nonsignificant in old age, and telomere length did not predict 7-year total mortality. CONCLUSIONS: We conclude that smoking and overweight in midlife, irrespective of glucose, cholesterol and blood pressure, are related to shorter leukocyte telomeres in old men. Telomere length in old age did not predict total mortality possibly due to competing causes.

Effects of long-term parenteral nutrition on serum lipids, plant sterols, cholesterol metabolism, and liver histology in pediatric intestinal failure.

BACKGROUND AND OBJECTIVE: Plant sterols (PS) in parenteral nutrition (PN) may contribute to intestinal failure-associated liver disease. We investigated interrelations between serum PS, liver function and histology, cholesterol metabolism, and characteristics of PN. PATIENTS AND METHODS: Eleven patients with intestinal failure (mean age 6.3 years) receiving long-term PN were studied prospectively (mean 254 days) and underwent repeated measurements of serum lipids, noncholesterol sterols, including PS, and liver enzymes. PS contents of PN were analyzed. Liver biopsy was obtained in 8 patients. Twenty healthy children (mean age 5.7 years) served as controls. RESULTS: Median percentage of parenteral energy of total daily energy (PN%) was 48%, including 0.9 g · kg(-1) · day(-1) of lipids. Respective amounts of PN sitosterol, campesterol, avenasterol, and stigmasterol were 683, 71, 57, and 45 µg · kg(-1) · day(-1). Median serum concentrations of sitosterol (48 vs 7.5 µmol/L, P < 0.001), avenasterol (2.9 vs 1.9, P < 0.01), stigmasterol (1.9 vs 1.2, P < 0.005), but not that of campesterol (9.8 vs 12, P = 0.22), were increased among patients in relation to controls, and correlated with PN% (r = 0.81-0.88, P < 0.005), but not with PN fat. Serum cholesterol precursors were higher in patients than in controls. Serum liver enzymes remained close to normal range. Glutamyl transferase correlated with serum PS (r = 0.61-0.62, P < 0.05). Liver fibrosis in 5 patients reflected increased serum PS (r = 0.55-0.60, P = 0.16-0.12). CONCLUSIONS: Serum PS moderately increase during olive oil-based PN, and correlate positively with PN% and glutamyl transferase. Despite well-preserved liver function, histology often revealed significant liver damage.

Plant stanol esters lower LDL cholesterol level in statin-treated subjects with type 1 diabetes by interfering the absorption and synthesis of cholesterol.

OBJECTIVE: We investigated the effects of plant stanol esters (STAEST) on serum cholesterol and lipoprotein lipid concentrations and serum non-cholesterol sterols in patients with type 1 diabetes who were on statin treatment. METHODS: In a randomized, double-blind, parallel study the intervention group (n=12) consumed vegetable oil-based spread enriched with STAEST (3.0 g/d of plant stanols), and the control group (n=12) consumed the same spread containing no added plant stanols for 4 weeks. RESULTS: Serum total, LDL and non-HDL cholesterol concentrations were decreased by 9.6, 16.4 and 15.3% compared with the baseline concentrations in the STAEST group (P<0.05 for all). The respective reductions were 7.8, 14.8 and 12.2% compared with the controls (P<0.05 for all). No effects on HDL cholesterol or serum triglyceride concentrations were found. The STAEST consumption significantly decreased serum plant sterol concentrations and the ratios to cholesterol by 30-32 and 25-27% (P<0.05 for all) compared with the baseline levels, respectively. Cholesterol synthesis markers were not increased in the STAEST group, but serum lathosterol to campesterol ratio was significantly increased by 57% compared with the baseline levels indicating increased cholesterol synthesis at least to some extent in compensation for decreased cholesterol absorption. However, cholesterol homeostasis, intact at baseline and in the control group also during the intervention was lost in the STAEST group. CONCLUSION: STAEST significantly decreased serum total, LDL and non-HDL cholesterol concentrations and thus offers an additional benefit to cholesterol lowering in patients with type 1 diabetes who are on statin treatment.

Prognostic significance of serum cholesterol, lathosterol, and sitosterol in old age; a 17-year population study.

BACKGROUND. Low serum total cholesterol is frequently associated with worse survival in older people, but mechanisms of this association are poorly understood. AIMS. Characteristics of cholesterol metabolism were related to survival in a random 75 + population sample. METHODS. Serum cholesterol and lathosterol, and sitosterol were measured in random persons (n = 623) of birth cohorts (1904, 1909, and 1914) in 1990, and all persons were followed for 17 years. RESULTS. Total cholesterol declined in old age, and low cholesterol was associated with poor health and multi-morbidity. Cholesterol below 5.0 mmol/L was associated with accelerated all-cause mortality (age- and gender-adjusted hazard ratio (HR) 1.54; 95% CI 1.21-1.97; P < 0.001) and vascular mortality (HR 2.13 (1.42-3.07); P < 0.001). Lathosterol (indicating cholesterol synthesis) and sitosterol (indicating cholesterol absorption) also decreased with deteriorating health. Low lathosterol, sitosterol, and cholesterol predicted mortality additively and independently of each other. When all three sterols were high (> median) or low, the age- and gender-adjusted survival was 9.9 and 5.6 years (P < 0.001). CONCLUSION. Lower synthesis and absorption of cholesterol, and low serum cholesterol level are associated with deteriorating health and indicate impaired survival in old age.

Cholesterol synthesis is increased and absorption decreased in non-alcoholic fatty liver disease independent of obesity.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) is associated with impaired glucose and lipoprotein metabolism. However, the metabolism of cholesterol in NAFLD remains unexplored. We investigated how fatty liver influences cholesterol metabolism in 242 non-diabetic subjects. METHODS: Liver fat content was measured with proton magnetic resonance spectroscopy. Cholesterol metabolism was assayed with serum non-cholesterol sterols, surrogate markers of cholesterol synthesis and absorption. The analyses were performed with gas-liquid chromatography. RESULTS: A total of 114 subjects had NAFLD and 128 subjects had normal liver fat content. Non-cholesterol sterols reflecting cholesterol synthesis (cholestenol, desmosterol, and lathosterol) were higher, and those reflecting cholesterol absorption (cholestanol and plant sterols) were lower in subjects with NAFLD than in controls, independent of body mass index. Liver fat content was positively associated with markers of cholesterol synthesis (r = from 0.262 to 0.344, p < 0.001 for all) and inversely associated with markers of cholesterol absorption (r = from -0.299 to -0.336, p < 0.001 for all). In the entire study group, synthesis and absorption markers were interrelated, indicating that the homeostasis of cholesterol metabolism was maintained. LDL cholesterol was similar in the two groups. CONCLUSIONS: We demonstrated that although LDL cholesterol concentrations are unchanged, cholesterol metabolism in NAFLD is characterized by increased synthesis and diminished absorption of cholesterol. These changes are associated with liver fat content independent of body weight.

Surrogate markers of cholesterol metabolism in children with native liver after successful portoenterostomy for biliary atresia.

PURPOSE: Cholestasis gradually ensues after portoenterostomy for biliary atresia (BA) and may deteriorate liver function. Cholesterol metabolism and its relationships with serum markers of liver function were evaluated in children living with native liver after successful portoenterostomy for BA. SUBJECTS AND METHODS: Serum lipids, noncholesterol sterol ratios to cholesterol, that is, surrogate markers of cholesterol metabolism, and liver function were cross-sectionally studied in 17 consecutive children after successful (postoperative bilirubin <20 micromol/L) portoenterostomy for BA with native liver and a mean age of 5.2 years. The results were compared with healthy age-matched controls. RESULTS: Mean serum total and low-density lipoprotein cholesterol and campesterol ratio were 18%, 43%, and 26% less than those of controls, respectively (P < .01 for all). Despite low serum cholesterol and campesterol (marker of cholesterol absorption) levels, serum lathosterol (marker of cholesterol synthesis) was decreased by 34% (P < .0001) from control levels and reflected serum prealbumin (r = 0.666) and cholestanol (r = -0.515, P < .05 for both). Cholestanol, twice higher than those of controls (P < .0001), reflected abnormally high serum alkaline phosphatase, glutamyl transferase, and bile acids (r = 0.558-0.711, P < .05). Serum campesterol was inversely related with lathosterol (r = -0.238, P < .05) in controls, but not in patients (r = -0.039). CONCLUSION: Children living with native liver after portoenterostomy for BA are inclined to low serum concentration and absorption of cholesterol. Cholesterol homeostasis was disturbed so that low cholesterol absorption was not associated with compensatory increase in cholesterol synthesis that decreased together with worsening of cholestasis.

Cholesterol metabolism in pediatric short bowel syndrome after weaning off parenteral nutrition.

BACKGROUND: Small intestine essentially regulates cholesterol homeostasis. AIMS: To evaluate cholesterol metabolism in short bowel syndrome (SBS). METHODS: Cholesterol precursors (e.g., cholestenol, desmosterol and lathosterol) and plant sterols (campesterol and sitosterol), respective markers of cholesterol synthesis and absorption, were determined in SBS patients (n=12) an average of 31 months after weaning off parenteral nutrition and in age-matched controls (n=80). RESULTS: Among patients, serum cholesterol precursor sterol to cholesterol ratios were 2-10 times higher (P<0.0001 for each). Those without any remaining ileum had 1.2-2.8 times higher precursor sterol to cholesterol ratios than those with an ileal remnant (P<0.05 for each). Serum cholesterol concentration, campesterol/cholesterol and campesterol/sitosterol were 34-39% lower (P<0.05 for each) in relation to controls. Bile acid absorption was markedly impaired (2.4 (0.2-3.2)%). Plant sterol ratios reflected the absolute length of remaining jejunum (r=0.625-0.663), and precursor sterol ratios inversely that of ileum (r=-0.589 to 0.750, P<0.05 for all). CONCLUSION: After weaning off parenteral nutrition, patients with pediatric onset SBS continue to have marked intestinal malabsorption of bile acids and moderate cholesterol malabsorption resulting in decreased serum cholesterol despite a marked compensatory increase in cholesterol synthesis.

Leisure-time physical activity, cardiovascular risk factors and mortality during a 34-year follow-up in men.

UNLABELLED: The inverse relationship between physical activity and mortality may be confounded by socioeconomic factors, cardiovascular risk factors and inverse causality. We investigated long-term association between self-reported regular physical activity and mortality in a socioeconomically homogeneous, initially healthy middle-aged (mean age 47) male cohort (the Helsinki Businessmen Study). In 1974, the men were assessed with questionnaires, clinical and laboratory examinations. Cardiovascular disease (CVD) risk factors (including body mass index [BMI], age, cholesterol, glucose, systolic blood pressure and smoking) and details of physical activity of 782 men were available. Leisure time physical activity was collapsed into 3 categories: low (n = 148), moderate (n = 398) and high activity (n = 236). Physical activity was also briefly assessed in questionnaire surveys in 1985-1986 and in 2000. Total mortality up to 2007 was retrieved from the Central Population Register. Altogether 295 men (37.7%) died during the 34-year follow-up, and leisure-time physical activity was significantly related to mortality in a step-wise manner: 45.9% (n = 68), 37.7% (n = 150), and 32.6% (n = 77) died in the low, moderate, and high activity groups, respectively (P < 0.001). With high activity group as referent and adjusted for midlife CVD risk, perceived health and fitness at baseline, hazard ratio for total mortality was 1.21 (95% confidence interval: 0.90, 1.62), and 1.61 (95% confidence interval: 1.13, 2.30) in the moderate and low activity groups, respectively. CONCLUSION: During the 34-year follow-up, leisure-time physical activity in initially healthy middle-aged men had a graded association with reduced mortality that was independent of CVD risk, glucose and BMI.

Insulin sensitivity regulates cholesterol metabolism to a greater extent than obesity: lessons from the METSIM Study.

Cholesterol synthesis is upregulated and absorption downregulated in insulin resistance and in type 2 diabetes. We investigated whether alterations in cholesterol metabolism are observed across the glucose tolerance status, from normoglycemia through impaired glucose tolerance to type 2 diabetes, in 781 randomly selected men 45 to 70 years of age from a population-based Metabolic Syndrome in Men Study. Cholesterol metabolism was assayed using surrogate serum markers, squalene, and noncholesterol sterols. The study population was classified into subgroups according to glucose tolerance as follows: normoglycemia, impaired fasting glucose, impaired glucose tolerance, and type 2 diabetes. LDL cholesterol did not differ between the groups. Cholesterol synthesis markers were lowest and absorption markers highest in normoglycemia. Sitosterol was lower in subjects with impaired fasting glucose compared with normoglycemic subjects (113 +/- 7 vs. 136 +/- 3 10(2) mumol/mmol of cholesterol, P < 0.05). LDL cholesterol was not associated with lathosterol/sitosterol ratio, a marker of cholesterol metabolism. Peripheral insulin sensitivity evaluated by the Matsuda index was associated with the lathosterol/sitosterol ratio in the entire population (r = -0.457, P < 0.001) and with that of lathosterol/cholestanol independently of obesity. In conclusion, cholesterol metabolism was altered already from subjects with impaired fasting glucose. Upregulated cholesterol synthesis was associated with peripheral insulin resistance independent of obesity.

The effect of a very high daily plant stanol ester intake on serum lipids, carotenoids, and fat-soluble vitamins.

BACKGROUND & AIMS: Intake of 2-3 g/d of plant stanols as esters lowers LDL cholesterol level, but there is no information about the efficacy and safety of a respective very high daily intake. We studied the effects of 8.8 g/d of plant stanols as esters on serum lipids and safety variables in subjects with mild to moderate hypercholesterolemia. METHODS: In a randomized, double-blind, placebo-controlled study the intervention (n=25) and control (n=24) groups consumed spread and drink enriched or not with plant stanol esters for 10 weeks. RESULTS: Plant stanols reduced serum total and LDL cholesterol concentrations by 12.8 and 17.3% from baseline and by 12.0 and 17.1% from controls (P<0.01 for all). Liver enzymes, markers of hemolysis, and blood cells were unchanged. Serum vitamins A, D, and gamma-tocopherol concentrations, and the ratios of alpha-tocopherol to cholesterol were unchanged. Serum beta-carotene concentrations decreased significantly from baseline and were different from controls even when adjusted for cholesterol. Serum alpha-carotene concentration and alpha-carotene/cholesterol ratio were not different from controls. CONCLUSIONS: High intake of plant stanols reduced LDL cholesterol values without any other side effects than reduction of serum beta-carotene concentration. However, the end product, serum vitamin A levels, were unchanged. The results suggest that plant stanol ester intake can be increased to induce a greater cholesterol lowering effect.