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L Karjalainen

Publications and source records attributed to L Karjalainen.

12 recordsLinked to original sources
PubMed2001

The hormone sensitive lipase gene in familial combined hyperlipidemia and insulin resistance.

BACKGROUND: Insulin resistance in the most common familial dyslipidemia, familial combined hyperlipidemia (FCHL), could be due to variations in the hormone sensitive lipase (HSL) gene. MATERIALS AND METHODS: The coding region of the HSL gene was screened with the single strand conformation polymorphism analysis in probands of 27 FCHL families with 228 members. In addition, the C-60G promoter substitution of the HSL gene was determined by the restriction fragment length polymorphism analysis in these subjects. RESULTS: No variants in the coding region of the HSL gene were found and the allele frequencies of the C-60G promoter substitution and the silent variant (G3138A) in the 3' untranslated region did not differ between 110 control subjects and 27 probands with FCHL. However, in control women the C-60G substitution was associated with high body mass index [30.6 +/- 0.9 kg m(-2) (mean +/- SD) in subjects with the C/G genotype and 24.8 +/- 4.6 in subjects with the C/C genotype, P = 0.012], and in control men with high rates of insulin-stimulated whole body glucose uptake (70.1 +/- 14.7 vs. 56.7 +/- 14.2 micromol kg(-1) min(-1), P = 0.014). In 228 FCHL family members this substitution was associated with high low-density lipoprotein cholesterol levels in men (4.51 +/- 1.12 vs. 5.17 +/- 1.28 mmol L(-1), P = 0.049), but not in women. CONCLUSIONS: The HSL gene is not a major gene for FCHL. However, the - 60G allele of this gene may affect body weight, insulin sensitivity and serum cholesterol levels.

Adult↗
PubMed2000

The Pro12A1a substitution in the peroxisome proliferator activated receptor gamma 2 is associated with an insulin-sensitive phenotype in families with familial combined hyperlipidemia and in nondiabetic elderly subjects with dyslipidemia.

Dyslipidemias and insulin resistance often present simultaneously, as in familial combined hyperlipidemia (FCHL), and therefore may have a common genetic background. In our previous study the Pro12A1a substitution of peroxisome proliferator receptor gamma 2 (PPARgamma2) associated with insulin sensitivity, low body mass index (BMI) and high-density lipoprotein (HDL) cholesterol levels. In this study, we investigated the role of this substitution in dyslipidemias. Therefore, 228 nondiabetic members of FCHL families and 866 nondiabetic elderly subjects with (n=217) and without dyslipidemia (n=649) were genotyped. The allele frequencies of the Pro12A1a substitution did not differ between elderly subjects with or without dyslipidemia or 27 probands with FCHL. However, this substitution was associated with low fasting insulin levels both in FCHL family members (P = 0.036 adjusted for gender and age) and elderly subjects with dyslipidemia (P=0.050) but not in elderly subjects without dyslipidemia (P=0.080). In addition, the Ala12 allele of PPARgamma2 was associated with low BMI (P= 0.034) and low total triglycerides (P=0.027), and increased HDL-cholesterol (P < 0.001) in elderly subjects with dyslipidemia (n=299) but not among any other study groups. We conclude that the Ala12 isoform of PPARgamma2 ameliorates the insulin resistance and unfavorable lipid and lipoprotein profiles in FCHL and hyperlipidemic elderly subjects.

Adult↗
PubMed2000

Impaired free fatty acid suppression during hyperinsulinemia is a characteristic finding in familial combined hyperlipidemia, but insulin resistance is observed only in hypertriglyceridemic patients.

Insulin resistance has been associated with hypertriglyceridemia, combined hyperlipidemia, and familial combined hyperlipidemia (FCHL). Whether all FCHL patients with different types of dyslipidemia have low insulin sensitivity has not been evaluated. We measured insulin sensitivity by the hyperinsulinemic euglycemic clamp with indirect calorimetry in 110 healthy controls and in 105 nondiabetic, FCHL family members: in 50 without dyslipidemia, in 19 with hypercholesterolemia (total cholesterol >/=7.7 mmol/L), in 22 with hypertriglyceridemia (total triglycerides >/=2.4 mmol/L in men 2.4 mmol/L in women), and in 14 with combined hyperlipidemia. During the hyperinsulinemic clamp, FCHL family members had higher free fatty acid levels than did controls (0.06+/-0.06 [mean+/-SD] in controls versus 0.16+/-0.11 in relatives without dyslipidemia versus 0.15+/-0. 07 in hypercholesterolemic patients versus 0.29+/-0.14 in hypertriglyceridemic patients versus 0.27+/-0.17 mmol/L in patients with combined hyperlipidemia; P<0.001 after adjustment for age, sex, and body mass index). Relatives without dyslipidemia (16.4+/-4.4 micromol. kg(-1). min(-1), P=0.001) and patients with hypertriglyceridemia (12.8+/-3.8 micromol. kg(-1). min(-1), P<0.001) and with combined hyperlipidemia (13.7+/-3.1 micromol. kg(-1). min(-1), P<0.001) had lower rates of insulin-stimulated glucose oxidation than did controls (19.4+/-4.7 micromol. kg(-1). min(-1)). Also, the rates of nonoxidative glucose disposal were lower in patients with hypertriglyceridemia (P=0.001) and combined hyperlipidemia (P=0.011) than in controls. In contrast, subjects with hypercholesterolemia and control subjects had similar rates of insulin-stimulated glucose uptake. We conclude that a defect in free fatty acid suppression during hyperinsulinemia, probably located in adipose tissue, is characteristic for all FCHL patients with varying types of dyslipidemia, whereas insulin resistance in skeletal muscle is observed only in FCHL patients with elevated triglyceride levels.

Adult↗
PubMed2000

G-250A substitution in promoter of hepatic lipase gene is associated with dyslipidemia and insulin resistance in healthy control subjects and in members of families with familial combined hyperlipidemia.

Low activity of hepatic lipase (HL) has been associated with high levels of triglycerides and high density lipoproteins, but the association of the HL promoter variants with insulin sensitivity has not been investigated. Therefore, in this study, the relationship of the G-250A promoter variant of the HL gene to the rates of insulin-stimulated glucose uptake measured by the hyperinsulinemic euglycemic clamp was investigated in 110 control subjects (82 men and 28 women, aged 50.7+/-7.6 [mean+/-SD] years, body mass index 26. 1+/-3.6 kg/m(2)) and in 105 first-degree relatives (65 men and 40 women, aged 47.8+/-16.0 years, body mass index 26.9+/-5.3 kg/m(2)) of 34 families with familial combined hyperlipidemia (FCHL). The A-250 allele of the HL promoter was associated with low rates of insulin-stimulated whole-body nonoxidative glucose disposal in control subjects (41.1+/-12.7 micromol. kg(-1). min(-1) in subjects with the G-250G genotype, 36.9+/-13.1 micromol. kg(-1). min(-1) in subjects with the G-250A genotype, and 29.9+/-13.5 micromol. kg(-1). min(-1) in subjects with the A-250A genotype; P=0.012 adjusted for age and sex) and with low rates of insulin-stimulated whole-body glucose oxidation in FCHL family members (16.7+/-4.2 versus 15.0+/-4. 4 versus 14.1+/-4.4 micromol. kg(-1). min(-1), P=0.024). In addition, the A-250 allele was associated with high levels of fasting insulin (P=0.047), very low density lipoprotein cholesterol (P=0.007), and total (P=0.009) and very low density lipoprotein (P=0.005) triglycerides in control subjects and with high levels of low density lipoprotein triglycerides (P=0.001) in FCHL family members (n=340). We conclude that the G-250A promoter variant of the HL gene is associated with dyslipidemia and insulin resistance. Mechanisms via which this polymorphism could affect insulin sensitivity remain to be elucidated.

Adult↗
PubMed1998

Different regulation of free fatty acid levels and glucose oxidation by the Trp64Arg polymorphism of the beta3-adrenergic receptor gene and the promoter variant (A-3826G) of the uncoupling protein 1 gene in familial combined hyperlipidemia.

Familial combined hyperlipidemia (FCHL) is characterized by variable expression of dyslipidemias and insulin resistance. Because the genetic background for FCHL is unknown, we investigated the effect of the Trp64Arg polymorphism of the beta3-adrenergic receptor (beta3-AR) gene and the promoter variant A --> G (-3826) of the uncoupling protein 1 (UCP1) gene on glucose and lipid metabolism in FCHL families. Both polymorphisms were screened in 228 members from 27 families with FCHL and in 82 control men from a random population sample. The frequency of the polymorphisms of the beta3-AR and UCP1 genes did not differ between patients with FCHL and controls. Although the rate of insulin-stimulated whole-body glucose uptake evaluated by the euglycemic clamp in family members of patients with FCHL was unaffected by both polymorphisms, subjects with the Trp64Arg genotype of the beta3-AR gene had higher rates of glucose oxidation (17.6+/-4.5 v 15.8+/-4.1 micromol/kg/min, P=.017) and lower levels of free fatty acids (FFAs) in the fasting state (0.56+/-0.27 v 0.61+/-0.28 mmol/L, P=.027) and during the euglycemic clamp (0.12+/-0.10 v 0.21+/-0.15 mmol/L, P=.041) than subjects with the Trp64Trp genotype. We conclude that in FCHL families, codon 64 polymorphism of the beta3-AR gene may influence the rate of glucose oxidation via FFA levels.

Abdomen↗
PubMed1998

Impaired insulin-stimulated glucose oxidation and free fatty acid suppression in patients with familial combined hyperlipidemia: a precursor defect for dyslipidemia?

Familial combined hyperlipidemia (FCHL) is characterized by hyperlipidemia and insulin resistance, but intracellular defect in insulin action is unknown. Therefore, we investigated insulin action by applying the hyperinsulinemic euglycemic clamp technique with indirect calorimetry in 58 FCHL family members (28 with FCHL; 30 without dyslipidemia; aged 49+/-12 years; body mass index [BMI], 25. 2+/-4.0 kg/m2) and in 72 healthy control subjects (aged 54+/-6 years; BMI, 26.3+/-3.1 kg/m2). In the fasting state, FCHL patients had higher levels of total cholesterol, total triglycerides, and apolipoprotein B than control subjects (P<0.001 after adjustment for gender, age, and BMI). During the euglycemic clamp, FCHL patients had lower rates of glucose oxidation (15.93+/-3.55 versus 19.65+/-4. 60 micromol/kg/min; P=0.001) and higher rates of lipid oxidation (0. 15+/-0.13 versus 0.01+/-0.25 mg/kg/min; P=0.024), as well as higher levels of serum-free fatty acids (FFA) (0.24+/-0.17 versus 0.06+/-0. 06 mmol/L; P<0.001) compared with those of control subjects. Relatives without dyslipidemia differed similarly from control subjects with respect to rates of glucose and lipid oxidation and FFA suppression during the hyperinsulinemic clamp. In FCHL family members, during the euglycemic clamp FFAs correlated negatively with the rates of glucose oxidation (P<0.001) but not with the rates of glucose nonoxidation (P=0.408). In FCHL family members without dyslipidemia and in control subjects, FFAs during the clamp correlated positively with levels of total triglycerides (P<0.001) and very low density lipoprotein cholesterol (P=0.008). We conclude that in patients with FCHL, and also in their first-degree relatives, insulin's suppressive effect on FFA levels is impaired, which may precede dyslipidemia in FCHL.

Adult↗
PubMed1997

Risk for non-insulin-dependent diabetes in the normoglycaemic elderly is associated with impaired cognitive function.

We studied cognitive function in normoglycaemic elderly subjects at different risk levels for developing non-insulin-dependent diabetes mellitus (NIDDM) and in patients with NIDDM. Risk for NIDDM was considered increased if both 2 h glucose and insulin values on oral glucose tolerance testing were higher than the median in normoglycaemic subjects, and low if the respective values were lower than the median. The increased risk group showed impairment on tests of immediate and delayed memory, attention, visuomotor speed and verbal fluency. Moreover, the increased risk group did not differ from patients with NIDDM on any cognitive tests. Our results suggest that increased risk for NIDDM is associated with widely affected cognitive function in the normoglycaemic elderly, highlighting the importance of healthy living habits.

Aged↗
PubMed1997

Codon 54 polymorphism of the human intestinal fatty acid binding protein 2 gene is associated with dyslipidemias but not with insulin resistance in patients with familial combined hyperlipidemia.

Familial combined hyperlipidemia (FCHL) is associated with variable expression of dyslipidemias and insulin resistance. In nondiabetic Pima Indians an A to G substitution in codon 54 of the fatty acid binding protein 2 (FABP2) gene has been shown to be associated with insulin resistance. We screened the entire coding region of this gene by single-strand conformation polymorphism analysis in 24 probands (17 men and 7 women; age, 63.0 +/- 7.4 years [mean +/- SD]; body mass index [BMI], 27.7 +/- 4.2 kg/m2) who had FCHL and in 40 healthy men from a random population sample of 82 men (age, 54.0 +/- 5.0 years; BMI, 26.3 +/- 3.2 kg/m2). Insulin resistance was assessed with the euglycemic clamp in 58 subjects from FCHL families (14 probands with FCHL and 44 first-degree relatives of probands; 38 men and 20 women; age, 51.5 +/- 12.6 years; BMI, 25.5 +/- 3.9 kg/m2). We found three nucleotide substitution in the FABP2 gene: GCT to ACT (Ala-->Thr) in codon 54, GTA to GTG in codon 118, and GCGCA to GCACA in the 3'-noncoding region. Frequencies of these variants did not differ between the patients and control subjects. The Ala to Thr substitution in codon 54 was associated with a high lipid oxidation rate (P = .011 after adjustment for sex and family relationship), high HDL triglycerides (P = .042), and high LDL triglycerides (P = .013) but not with insulin resistance in subjects from FCHL families. The FABP2 gene is unlikely to be a major gene for FCHL, but it might affect lipid metabolism in subjects with FCHL.

Adult↗
PubMed1997

Estimates of genetic parameters and environmental effects for measures of hunting performance in Finnish hounds.

Data from field trials of Finnish Hounds between 1988 and 1992 in Finland were used to estimate genetic parameters and environmental effects for measures of hunting performance using REML procedures and an animal model. The original data set included 28,791 field trial records from 5,666 dogs. Males and females had equal hunting performance, whereas experience acquired by age improved trial results compared with results for young dogs (P < .001). Results were mostly better on snow than on bare ground (P < .001), and testing areas, years, months, and their interactions affected results (P < .001). Estimates of heritabilities and repeatabilities were low for most of the 28 measures, mainly due to large residual variances. The highest heritabilities were for frequency of tonguing (h2 = .15), pursuit score (h2 = .13), tongue score (h2 = .13), ghost trailing score (h2 = .12), and merit and final score (both h2 = .11). Estimates of phenotypic and genetic correlations were positive and moderate or high for search scores, pursuit scores, and final scores but lower for other studied measures. The results suggest that, due to low heritabilities, evaluation of breeding values for Finnish Hounds with respect to their hunting ability should be based on animal model BLUP methods instead of mere performance testing. The evaluation system of field trials should also be revised for more reliability.

Aging↗
PubMed1996

Effects of losartan on insulin sensitivity in hypertensive subjects.

Losartan, the first specific and orally available angiotensin II receptor antagonist, is a potent antihypertensive drug with a low incidence of side effects in humans. However, the effects of losartan on insulin sensitivity and glucose metabolism have not been investigated in detail. Therefore, we carried out a randomized, double-blind study to compare the effects of losartan (50 mg QD) and metoprolol (95 mg QD) on insulin sensitivity, insulin secretion, glucose tolerance, and lipids and lipoproteins in 20 hyperinsulinemic subjects with essential hypertension. The fall in blood pressure was greater with losartan than with metoprolol. Insulin sensitivity evaluated by the euglycemic clamp technique did not change in either group after 12 weeks of treatment. Similarly, glucose oxidation (losartan: 17.0 +/- 0.9 versus 16.9 +/- 1.0 mumol/kg per minute [before versus after, P = NS]; metoprolol: 17.9 +/- 1.3 versus 16.8 +/- 1.6 [P = NS]) and nonoxidation (losartan: 22.3 +/- 4.0 versus 23.5 +/- 3.4 mumol/kg per minute [P = NS]; metoprolol: 23.3 +/- 3.2 versus 25.6 +/- 4.7 [P = NS]) remained unchanged during the last 30 minutes of the 3-hour euglycemic clamp. Losartan and metoprolol did not have any significant adverse effects on insulin secretion, glucose tolerance, or lipids and lipoproteins. In conclusion, losartan is metabolically neutral, without any significant adverse effect on glucose and lipid metabolism.

Antihypertensive Agents↗
PubMedDate not supplied

Improvement of metabolic control does not normalize auditory brainstem latencies in subjects with insulin-dependent diabetes mellitus.

INTRODUCTION: In our previous study (Am J Otolaryngol 14:413-418, 1993), we reported that prolonged auditory brainstem response latencies are associated with microvascular complications and the duration of diabetes in patients with insulin-dependent diabetes mellitus (IDDM). To investigate whether short-term improvement in metabolic control also affects ABR-responses, we compared ABR-latencies in subjects with IDDM before and after intensified insulin and diet therapy. MATERIALS AND METHODS: Auditory brainstem latencies were measured in 13 subjects with IDDM (mean age: 25 years) before and after intensified insulin and diet therapy. The acoustic stimulus was a half sine wave with a duration of 0.250 millisecond and a frequency of 2,000 Hz. The stimulus was presented monaurally with fixed polarity through shielded headphones TDH-39 at repetition rate of 10 Hz and at 90 dB hearing level. All subjects had normal hearing ability. Glycated hemoglobin A1C (GHbA1C), blood glucose immediately before ABR-measurements, and mean blood glucose during 24 hours before auditory studies were measured before and after intensified therapy. RESULTS: During intensified insulin therapy, GHbA1C improved significantly (P < .05) in study subjects. However, no changes were observed in ABR-latencies. We also studied those 10 patients whose blood glucose improved during intensified insulin therapy. Although blood glucose was significantly lower (P < .01) after intensified insulin therapy compared with that at baseline, no changes were observed between ABR-latencies at baseline and follow-up. CONCLUSION: ABR-latencies were not affected by improvement in metabolic control in patients with IDDM. Our finding suggests that delayed ABR-latencies found in patients with IDDM are not caused by poor metabolic control of diabetes but rather by other mechanisms, for example, microvascular complications.

Adult↗