The impact of iron status and smoking on blood divalent metal concentrations in Norwegian women in the HUNT2 Study.

Low iron (Fe) stores may result in increased absorption of divalent metals, in particular cadmium (Cd). We have previously shown that in non-smoking women participating in the Norwegian HUNT2 cohort study this also included other divalent metals, e.g. manganese (Mn) and cobalt (Co). The diet is the main source of metals in non-smoking individuals, whereas in smoking individuals tobacco smoke contributes significant amounts of Cd and lead (Pb). The aim of the present study was to investigate the impact of smoking on the relationship between low iron status and divalent metals. Blood concentrations of the divalent metals Cd, Mn, Co, Pb, copper (Cu) and zinc (Zn), determined using an Element 2 sector field mass spectrometer (ICP-MS), were investigated in smoking women of fertile age (range 21-55 years) (n=267) from the HUNT2 cohort. Among these, 82 were iron-deplete (serum ferritin<12µg/L) and 28 had iron deficiency anaemia (serum ferritin<12µg/L & Hb<120g/L). 150 (56%) women smoked 10 or more cigarettes daily, 101 (38%) had smoked for more than 20 years, and 107 (40%) had smoked for 11-20 years. Results from the smoking population were compared with results from our previous study in non-smoking women (n=448) of which 132 were previous smokers, all from the same cohort. Increasing concentrations of Cd in blood were observed for previous smokers, low-to-moderate smokers and high intensity smokers in all subgroups compared to never smokers, and according to age groups, education level, BMI and serum ferritin. Smokers had higher Pb concentrations than non-smokers in all subgroups, but less pronounced than for Cd. Smoking was not associated with Mn and Co concentrations in blood. In multiple regression models, low ferritin was associated with increased blood concentrations of Cd, Pb, Mn and Co. Ferritin was strongly associated with Cd at low smoking intensity, but was not a significant factor in heavy smokers, where intensity and duration of smoking emerged as main determinants. Ferritin associations with Co and Pb varied with tertiles of blood Cd. Ferritin emerged as the main determinant of blood Co and Mn, while for blood Pb, age and smoking intensity had higher impact. Cu and Zn remained within reference values and no significant associations with ferritin were found. Strong positive associations between blood concentrations of Pb, Mn, Cd and Co were observed, also when controlled for their common association with ferritin. Apart from these associations, the models showed no significant interactions between the divalent metals studied. Mild anaemia (110

Trends in overweight and obesity over 22 years in a large adult population: the HUNT Study, Norway.

Some reports indicate that the obesity epidemic may be slowing down or halting. We followed body mass index (BMI) and waist circumference (WC) in a large adult population in Norway (n = 90 000) from 1984-1986 (HUNT1) through 1995-1997 (HUNT2) to 2006-2008 (HUNT3) to study whether this is occurring in Norway. Height and weight were measured with standardized and identical methods in all three surveys; WC was also measured in HUNT2 and HUNT3. In the three surveys, mean BMI increased from 25.3 to 26.5 and 27.5 kg m-2 in men and from 25.1 to 26.2 and 26.9 kg m-2 in women. Increase in prevalence of obesity (BMI ≥ 30 kg m-2) was greater in men (from 7.7 to 14.4 and 22.1%) compared with women (from 13.3 to 18.3 and 23.1%). In contrast, women had a greater increase in abdominal obesity (WC ≥ 102 cm for men and WC ≥ 88 cm for women). There was a continuous shift in the distribution curve of BMI and WC to the right, demonstrating that the increase in body weight was occurring in all weight groups, but the increase of obesity was greatest in the youngest age groups. Our data showed no signs of a halt in the increase of obesity in this representative Norwegian population.

Low 25-hydroxyvitamin D level is independently associated with non-alcoholic fatty liver disease.

BACKGROUND AND AIMS: We sought to explore associations between serum 25-hydroxyvitamin D [25(OH)D] levels and non-alcoholic fatty liver disease [NAFLD] in an integrated healthcare delivery system in the U.S. METHODS AND RESULTS: Six hundred and seven NAFLD cases were randomly matched 1:1 with controls for age, sex, race and season of measurement. Conditional logistic regression was used to evaluate if serum 25(OH)D levels were associated with increased odds of NAFLD (diagnosed by ultrasound) after adjusting for body mass index and history of diabetes, renal, peripheral vascular and liver diseases (model 1) and also for hypertension (model 2). Mean (SD) serum 25(OH)D level was significantly lower in the group with NAFLD as compared with that in the matched control group (75 ± 17 vs. 85 ± 20 nmol/L [30 ± 7 vs. 34 ± 8 ng/mL], P<0.001). Inadequate 25(OH)D status progressively increased the odds of NAFLD when classified categorically as sufficient (25(OH)D 75 nmol/L [>30 ng/mL], reference group), insufficient (37-75 nmol/L [15-30 ng/mL]; adjusted odds ratio [OR]: 2.40, 95% confidence interval [CI]: 0.90-6.34) or deficient (<37 nmol/L [<15 ng/mL]; adjusted OR: 2.56, 95% CI: 1.27-5.19). When modeled as a continuous variable, increased log10 25(OH)D was inversely associated with the risk of prevalent NAFLD (adjusted OR: 0.25, 95% CI: 0.064-0.96, P=0.02). CONCLUSION: Compared with matched controls, patients with NAFLD have significantly decreased serum 25(OH)D levels, suggesting that low 25(OH)D status might play a role in the development and progression of NAFLD.

Cohort Profile: the HUNT Study, Norway.

The HUNT Study includes large total population-based cohorts from the 1980ies, covering 125 000 Norwegian participants; HUNT1 (1984-86), HUNT2 (1995-97) and HUNT3 (2006-08). The study was primarily set up to address arterial hypertension, diabetes, screening of tuberculosis, and quality of life. However, the scope has expanded over time. In the latest survey a state of the art biobank was established, with availability of biomaterial for decades ahead. The three population based surveys now contribute to important knowledge regarding health related lifestyle, prevalence and incidence of somatic and mental illness and disease, health determinants, and associations between disease phenotypes and genotypes. Every citizen of Nord-Trøndelag County in Norway being 20 years or older, have been invited to all the surveys for adults. Participants may be linked in families and followed up longitudinally between the surveys and in several national health- and other registers covering the total population. The HUNT Study includes data from questionnaires, interviews, clinical measurements and biological samples (blood and urine). The questionnaires included questions on socioeconomic conditions, health related behaviours, symptoms, illnesses and diseases. Data from the HUNT Study are available for researchers who satisfy some basic requirements (www.ntnu.edu/hunt), whether affiliated in Norway or abroad.

Headache, migraine and cardiovascular risk factors: the HUNT study.

BACKGROUND: Migraine with aura (MA) has been found to be a risk factor for cardiovascular disease including ischaemic stroke and myocardial infarction. Studies have also reported a higher prevalence of unfavourable cardiovascular risk factors amongst migraineurs, but results have been conflicting as to whether this is restricted to MA or also holds true for migraine without aura (MO). This study aims to examine the relation between headache and cardiovascular risk factors in a large cross-sectional population-based study. METHODS: A total of 48,713 subjects (age ≥ 20 years) completed a headache questionnaire and were classified according to the headache status in the Nord-Trøndelag Health Study in Norway 1995-1997 (HUNT 2). Framingham 10-year risk for myocardial infarction and coronary death could be calculated for 44,098 (90.5%) of these. Parameters measured were blood pressure, body mass index, serum total and high-density lipoprotein cholesterol. RESULTS: Compared to controls, Framingham risk score was elevated in non-migraine headache sufferers (OR 1.17, 95% CI 1.10-1.26), migraineurs without aura (OR 1.17, 95% CI 1.04-1.32) and most pronounced amongst migraineurs with aura (OR 1.54, 95% CI 1.21-1.95). Framingham risk score consistently increased with headache frequency. For non-migrainous headache and MO, the increased risk was accounted for by the lifestyle factors smoking, high BMI and low physical activity, whilst such factors did not explain the elevated risk associated with MA. CONCLUSIONS: Both MA, MO and non-migrainous headache are associated with an unfavourable cardiovascular risk profile, but different mechanisms seem to underlie the elevated risk in MA than in the other headache types.

FTO genotype and weight gain in obese and normal weight adults from a Norwegian population based cohort (the HUNT study).

The fat mass and obesity associated gene ( FTO) is associated with bodyweight and obesity. The aim of this study was to investigate if FTO genotype affects weight gain in adulthood. We investigated the weight development over a period of 11 years in a case-control study, consisting of 1,632 cases (BMI≥35 kg/m (2)) and 3,379 normal weight controls (BMI 20-24.9 kg/m (2)) from a Norwegian population based cohort, the HUNT study. Subjects were aged 20-80 at baseline, 25% men and 75% women. FTO genotype was assessed by genotyping of the SNP rs1421085. A strong association between FTO and obesity was found, consistent with an additive gene effect. Cases had an average weight gain of 11.1 kg, whereas controls had an average weight gain of 1.4 kg. Genotype was neither associated with weight gain in obese, nor controls. Cases had an average weight gain of 10.7 kg for individuals with zero risk alleles, 11.3 for one risk allele and 11.1 kg for two risk alleles. Controls had an average weight gain of 1.4 kg, 1.4 and 1.3 for the respective genotypes. In conclusion, FTO was associated with obesity, but not with weight gain in adults during 11 years of follow-up.

Comparison of genetic risk in three candidate genes (TCF7L2, PPARG, KCNJ11) with traditional risk factors for type 2 diabetes in a population-based study--the HUNT study.

UNLABELLED: We studied the impact of genetic and traditional risk factors for type 2 diabetes in a large, population-based study from Nord-Trøndelag county in Norway (HUNT), in both cross-sectional and prospective design. MATERIAL AND METHODS: 65,905 individuals participated in the HUNT study. We studied a randomly selected group of 869 individuals with self-reported diabetes or non-fasting serum glucose >or=11.1 mmol/L and 2,080 non-diabetic control subjects with non-fasting serum glucose <5.5 mmol/L. Four candidate polymorphisms in the three genes TCF7L2 (rs12255372 and rs7903146), PPARG (rs1801282), KCNJ11 (rs5219) and traditional risk factors were studied. RESULTS: Risk alleles of the TCF7L2 gene showed increased risk of diabetes even when controlled for traditional diabetes risk factors (diabetes in family, waist circumference, physical activity, BMI, SBP and total and HDL-cholesterol) in both a cross-sectional and prospective setting (cross-sectional: rs12255372 OR 1.61 (1.31-1.99), rs7903146 OR 1.48 (1.20-1.83) and prospective: rs12255372 OR 1.59 (1.22-2.07), rs7903146 OR 1.47 (1.11-1.93)). The risk alleles of TCF7L2 indicated impaired beta-cell function in patients and control subjects. The population attributable risks for diabetes with TCF7L2 risk alleles were 15 % and with diabetes in a first-degree relative 31 %. CONCLUSION: The risk alleles of the TCF7L2 gene (rs12255372 and rs7903146) were strongly associated with type 2 diabetes, even after controlling for traditional risk factors in both a cross-sectional and prospective setting. These risk alleles were associated with indices of reduced beta-cell function.

High pulse pressure protects against headache: prospective and cross-sectional data (HUNT study).

BACKGROUND: Many antihypertensive drugs are also used as migraine prophylactics, but the relationship between blood pressure and headache is not been well understood. The objective of the present study was to explore the association between blood pressure and headache prevalence, and the effect of antihypertensive medication on this relationship, using both cross-sectional and prospective data from a large population. METHODS: We used data from two large epidemiologic studies, the Nord-Trøndelag Health Survey 1984-1986 (HUNT-1) and 1995-97 (HUNT-2), to evaluate the association between blood pressure (systolic, diastolic, mean arterial, and pulse pressure) and migraine and nonmigrainous headache. RESULTS: Increasing systolic blood pressure was associated with decreasing prevalence of having nonmigrainous headache or migraine. The most consistent and robust finding, however, was that increasing pulse pressure was linked to decreased prevalence of both nonmigrainous headache and migraine, evident for both sexes in the prospective and cross-sectional analyses. In subjects using antihypertensive medication, this finding was less clear. CONCLUSION: Both increased systolic blood pressure and pulse pressure are related to arterial stiffness and may decrease headache prevalence through modulation of the baroreflex arch, which in turn generates hypoalgesia. This is due to a phenomenon called hypertension-associated hypalgesia. Stimulation of the baroreflex arch in response to increased blood pressure is assumed to inhibit pain transmission at both spinal and supraspinal levels, possibly because of an interaction of the centers modulating nociception and cardiovascular reflexes in the brainstem.

Blood pressure and renal cancer risk: the HUNT Study in Norway.

In a prospective study of 36,728 women and 35,688 men during 18 years of follow-up, compared to systolic pressure <130 mm Hg, levels of 130-149, 150-169 and >or=170 mm Hg in women were associated with relative risks of renal cell cancer of 1.7, 2.0 and 2.0, respectively (P for linear trend, 0.11). In men, there was no association with blood pressure.

Change in height, weight and body mass index: Longitudinal data from the HUNT Study in Norway.

OBJECTIVE: The aim of this study was to analyse changes in body weight and height, and the changes in the prevalence of overweight and obesity. DESIGN: Prospective population based study with 11-year follow-up. SUBJECTS: Norwegian men (n=21565) and women (n=24337) aged 20 years or more who participated in two health surveys, the first in 1984-1986 and the other in 1995-1997. MEASUREMENTS: Height and weight were measured by using standardised procedures at both surveys, and we computed body mass index (BMI) as weight in kilo divided by the squared value of height in meters. RESULTS: Participants who were younger than 50 years at the first survey showed a large increase in body weight, and men and women aged 20-29 years increased their weight with an average of 7.9 kg and 7.3 kg, respectively. Contradictory, participants who were 70 years or older had on average a weight loss. The prevalence of overweight (BMI=25.0-29.9 kg/m(2)) and obesity (BMI>/=30 kg/m(2)) increased between the surveys, especially in the youngest age groups. Overall, the proportion classified as obese increased from 6.7 to 15.5% among men and from 11.0 to 21.0% among women. Some of this increase was due to a reduction in height, which was most pronounced in the oldest age groups. CONCLUSION: During approximately 10 years, body weight increased in all age groups below 70 years, and the prevalence of overweight and obese persons was approximately 20% higher at the second survey compared with the first survey.

Change in body mass index and its impact on blood pressure: a prospective population study.

BACKGROUND: Overweight and obesity increase the risk of elevated blood pressure, but the knowledge of the effect of weight change on blood pressure is sparse. OBJECTIVE: To investigate the association between change in body mass index (BMI) and change in diastolic blood pressure (DBP), systolic blood pressure (SBP), and hypertension status. DESIGN: Two population-based cross-sectional studies, one in 1984-86 and the other in 1995-97. SETTING: The Nord-Trondelag Health Study (HUNT). PARTICIPANTS: We included 15,971 women and 13,846 men who were 20 y or older at the first survey, without blood pressure medication at both surveys and without diabetes, cardiovascular disease or dysfunction in daily life at baseline. MEASUREMENTS: Weight, height and blood pressure were measured standardised. Change in BMI was categorised as stable (initial BMI+/-0.1 kg/m2 each follow-up year), increased or decreased, and BMI was categorised by using World Health Organisation's categorisation (underweight BMI: <18.5 kg/m2, normal weight BMI: 18.5-24.9 kg/m2, overweight BMI: 25.0-29.9 kg/m2, obesity BMI> or =30 kg/m2). RESULTS: An increase in BMI and a decrease in BMI were significantly associated with increased and decreased SBP and DBP, respectively, compared to a stable BMI in both genders and all age groups, although the strongest effect was found among those who were 50 y and older. The adjusted odds ratio for having hypertension at HUNT 2 was 1.8 (95% confidence interval (CI): 1.5, 2.2) among women and 1.6 (95% CI: 1.4,1.8) among men aged 20-49 y who increased their BMI compared to those who had stable BMI. A similar, but weaker association was found among women and men aged 50 y or more. The mean change in both SBP and DBP was higher for those who changed BMI category from first to the second survey than for those who were in the same BMI class at both surveys. CONCLUSIONS: Our result supports an independent effect of change in BMI on change in SBP and DBP in both women and men, and that people who increase their BMI are at increased risk for hypertension.

Weight change and mortality: the Nord-Trøndelag Health Study.

OBJECTIVES: The prevalence of obesity is increasing. Overweight and obese people have increased mortality compared with normal weight people. We investigated the effect of weight change on mortality. DESIGN: Prospective population study. SETTING: We utilized data from two large population-based health studies conducted in 1984-86 and 1995-97 respectively. Cox proportional hazards models were used to calculate mortality rate ratios (RRs) with 95% confidence intervals (CIs) between people with a stable weight and people who lost or gained weight. Subjects. Totally 20,542 men and 23,712 women aged 20 years or more, without cardiovascular disease or diabetes at the first survey and without a history of cancer at the second survey were followed up on all-cause mortality for 5 years after the second survey. RESULTS: We found no association between weight gain and mortality. People who lost weight had a higher total mortality rate compared with those who were weight stable [RR was 1.6 (95% CI: 1.4-1.8) in men and 1.7 (95% CI: 1.5-2.0) in women]. Similar associations were found for cardiovascular and noncardiovascular mortality. Additional analysis showed a linear increase in mortality rates across categories of weight loss for both men and women (P < 0.001). There was a statistically significant interaction between weight change and initial BMI, but only amongst men (P = 0.001). CONCLUSIONS: Weight loss, but not weight gain, was associated with increased mortality amongst men and women. Although underlying undiagnosed disease is the most plausible explanation for this finding, the similar associations found for total mortality, cardiovascular mortality, and noncardiovascular mortality makes the causal pathway somewhat enigmatic.

Analgesic overuse among subjects with headache, neck, and low-back pain.

OBJECTIVES: To examine the prevalence of chronic headache (> or =15 days/month) associated with analgesic overuse in relation to age and gender and the association between analgesic overuse and chronic pain (i.e., migraine, nonmigrainous headache, neck and low-back pain). METHODS: In the Nord-Trøndelag Health Study 1995 to 1997 (HUNT-2), a total of 51,383 subjects responded to headache questions (Head-HUNT), of which 51,050 completed questions related to musculoskeletal symptoms and 49,064 questions regarding the use of analgesics. RESULTS: The prevalence of chronic headache associated with analgesic use daily or almost daily for > or =1 month was 1% (1.3% for women and 0.7% for men) and for analgesic overuse duration of > or =3 months 0.9% (1.2% for women and 0.6% for men). Chronic headache was more than seven times more likely among those with analgesic overuse (> or =1 month) than those without (odds ratio [OR] = 7.5, 95% CI: 6.6 to 8.5). Upon analysis of the different chronic pain subgroups separately, the association with analgesic overuse was strongest for chronic migraine (OR = 10.3, 95% CI: 8.1 to 13.0), intermediate for chronic nonmigrainous headache (OR = 6.2, 95% CI: 5.3 to 7.2), and weakest for chronic neck (OR = 2.6, 95% CI: 2.3 to 2.9) and chronic low-back (OR = 3.0, 95% CI: 2.7 to 3.3) pain. The association became stronger with increasing duration of analgesic use for all groups and was most evident among those with headache, especially those with migraine. CONCLUSIONS: Chronic headache associated with analgesic overuse is prevalent and especially chronic migraine is more strongly associated with frequent intake of analgesics than other common pain conditions like chronic neck and chronic low-back pain.

BMI change and leisure time physical activity (LTPA): an 11-y follow-up study in apparently healthy men aged 20-69 y with normal weight at baseline.

OBJECTIVE: To study the association between self-reported leisure time physical activity (LTPA) at baseline and change in body mass index (BMI). DESIGN: Prospective observational study with a 11-y follow-up period. SETTING: A total population-based health survey in one county was performed in 1984-1986 (HUNT 1) and repeated in 1995-1997 (HUNT 2). PARTICIPANTS: In total, 21 685 men participated in both surveys. In the present study, we included only apparently healthy 20-69-y-old men participating in both surveys and who had a normal body weight (BMI 18.5-24.9 kg/m(2)) at baseline-leaving 8305 men for the analyses. In all, 6945 men answered all questions about LTPA and 6749 men had complete data in the multiple analyses. MEASUREMENTS AND MAIN RESULTS: At HUNT 1, the participants answered questions (self-reported) about the intensity, frequency and duration of LTPA. The association between change in BMI and LTPA was investigated in multiple linear regression analyses. Adjusted for smoking, education, age and BMI at baseline, the physical active cohort gained less weight than the inactive cohort. Low, moderate and high levels of LTPA showed a U-shaped effect adjusted for smoking, education, age and BMI at baseline. Adjusted for BMI and age at baseline, the high-intensity part of the physically active cohort gained less weight than the low-intensity group. CONCLUSION: This study has demonstrated a moderate BMI effect of LTPA at the population level; however, even a high level of LTPA did not prevent weight gain during the 11-y follow-up period.

Analgesic use: a predictor of chronic pain and medication overuse headache: the Head-HUNT Study.

OBJECTIVE: To examine the relation between analgesic use at baseline and the subsequent risk of chronic pain (> or =15 days/month) and the risk of analgesic overuse. METHODS: In total, 32, 067 adults reported the use of analgesics in 1984 to 1986 and at follow-up 11 years later (1995 to 1997). The risk ratios (RR) of chronic pain and RR of analgesic overuse in the different diagnostic groups (i.e., migraine, nonmigrainous headache, neck pain, and low-back pain) were estimated in relation to analgesic consumption at baseline. RESULTS: Individuals who reported use of analgesics daily or weekly at baseline showed significant increased risk for having chronic pain at follow-up. The risk was most evident for chronic migraine (RR = 13.3, 95% CI: 9.3 to 19.1), intermediate for chronic nonmigrainous headaches (RR = 6.2, 95% CI: 5.0 to 7.7), and lowest for chronic neck (RR = 2.4, 95% CI: 2.0 to 2.8) or chronic low-back (RR = 2.3, 95% CI: 2.0 to 2.8) pain. Among subjects with chronic pain associated with analgesic overuse, the RR was 37.6 (95% CI: 21.3 to 66.4) for chronic migraine, 14.4 (95% CI: 10.4 to 19.9) for chronic nonmigrainous headaches, 7.1 for chronic neck pain (95% CI: 5.5 to 9.2), and 6.4 for chronic low-back pain (95% CI: 4.9 to 8.4). The RR for chronic headache (migraine and nonmigrainous headache combined) associated with analgesic overuse was 19.6 (95% CI: 14.8 to 25.9) compared with 3.1 (95% CI: 2.4 to 4.2) for those without overuse. CONCLUSION: Overuse of analgesics strongly predicts chronic pain and chronic pain associated with analgesic overuse 11 years later, especially among those with chronic migraine.

Clinical relevance of microalbuminuria screening in self-reported non-diabetic/non-hypertensive persons identified in a large health screening--the Nord-Trøndelag Health Study (HUNT), Norway.

AIM: The aim of this study was to investigate the clinical relevance and consequences of screening for microalbuminuria (MA) in a randomly selected, apparently healthy population sample. MATERIAL AND METHODS: A total of 2,113 individuals (> or = 20 years) without known diabetes and treated hypertension, all identified in the large population-based Nord-Trøndelag Health Study (HUNT) 1995-1997, (n = 65,258), delivered 3 morning urine samples for MA analysis. Those with MA, defined as at least 2 out of 3 urine samples with albumin-to-creatinine ratio (ACR) > or = 2.5 mg/mmol, were invited to a second clinical examination. RESULTS: In total, 54 men and 54 women had MA, and 42 men (84%) and 42 women (78%) attended the second examination. All with MA had 1 or more cardiovascular risk factors, like elevated cholesterol, c-peptides and blood pressure, and they were older than those without MA. Ten men (25%) and 19 women (46%), who were defined as MA-positive at the screening, had normal albumin excretion in the overnight collected urine sample in the second clinical examination. Five men (12%) and 2 women (5%) were still followed-up at the hospital out-patient clinic 3 years later. CONCLUSIONS: Several individuals in the second examination had cardiovascular risk factors and other pathology, but the clinical benefit of discovering this was not obvious. Due to low positive predictive value and reduced reliability and validity, MA did not satisfy the criteria for a good screening test in this apparently healthy population.

Scheimpflug photography study of ophthalmic viscosurgical devices during simulated cataract surgery.

PURPOSE: To evaluate by Scheimpflug photography the capacity of several commercially available ophthalmic viscosurgical devices (OVDs) to remain in the anterior chamber and maintain anterior chamber depth (ACD) during simulated cataract surgery in porcine cadaver eyes. SETTING: Department of Preclinical Ophthalmology, Pharmacia & Upjohn AB, Uppsala, Sweden. METHODS: Eighty eyes from newly slaughtered pigs were used. They were distributed equally among 8 OVDs: Amvisc Plus (sodium hyaluronate 1.6%), Biolon (sodium hyaluronate 1.0%), Biolon Prime (sodium hyaluronate 1.2%), Healon (sodium hyaluronate 1.0%), Healon GV (sodium hyaluronate 1.4%), Healon5 (sodium hyaluronate 2.3%), Provisc (sodium hyaluronate 1.0%), and Viscoat (sodium hyaluronate 3.0%-chondroitin sulfate 4.0%). Scheimpflug photographs were taken using a Nidek EAS-1000 instrument before surgery (control), after injection of the OVD, after continuous curvilinear capsulorhexis (CCC), and after lens extraction by phacoemulsification. Differences in the ACD with a P value less than 0.05 were considered statistically significant. The retention capacity was visually assessed. RESULTS: Healon5 had a significantly higher capacity to maintain the ACD than the other OVDs after CCC and phacoemulsification. After injection, Healon5, Viscoat, and Biolon Prime showed similar ACD-maintaining capacities. CONCLUSIONS: The capacity of Healon5 to maintain the ACD during cataract surgery, ie, neutralizing the vitreous pressure and stabilizing the anterior segment of the eye, was significantly higher than that of the other OVDs.

Gender differences in the impact of adolescent smoking on lung function and respiratory symptoms. the Nord-Trøndelag Health Study, Norway, 1995-1997.

Girls take up smoking at least as frequently as boys. Few studies have focused on gender differences in the impact of adolescent smoking. We evaluated the sex-specific effect of adolescent smoking on respiratory symptoms and lung function. All students in junior high and high schools in Nord-Trøndelag County Norway, 1995-97, were invited to participate in a cross-sectional study. Information on smoking habits and respiratory symptoms was obtained by self-administered questionnaires. Spirometry was performed in accordance with ATS standards. Eight-thousand-three-hundred and five students (83%) completed both questionnaire and spirometry. Among 6811 students aged 13-18 years (50.3% girls) with no history of asthma, 2993 (43.9%) reported never smoking, 665 (98%) reported occasional smoking, and 667 (9.9%) reported daily smoking (mean initiation age: 13.9 years). More boys than girls were heavy smokers. In all smoking categories, smokers reported a higher prevalence of respiratory symptoms than nonsmokers; symptoms increased with smoke burden. Girls reported more symptoms compared to boys with comparable smoke burden. A dose-response relation between smoking and reduced lung function was found only in girls. Girls were more vulnerable than boys to the impact of smoking on respiratory symptoms and lung function.

Microalbuminuria, cardiovascular disease and risk factors in a nondiabetic/nonhypertensive population. The Nord-Trøndelag Health Study (HUNT, 1995-97), Norway.

OBJECTIVE: Microalbuminuria (MA) as an independent marker of cardiovascular morbidity and mortality in nondiabetic/nonhypertensive individuals is under international debate. The aim of this study was to investigate the associations between MA and known cardiovascular risk factors/markers and disease in a randomly selected nondiabetic/nonhypertensive sample. DESIGN: Cross-sectional study. SETTING: Participants in the population-based Nord-Trøndelag Health Study (HUNT), Norway (n = 65 258). SUBJECTS: A total of 2113 individuals (> or =20 years), randomly selected without diabetes and treated hypertension, delivered three morning urine samples for MA analysis. MAIN OUTCOME MEASURES: MA expressed as albumin-to-creatinine ratio (ACR), cardiovascular risk factors and disease. RESULTS: Increasing age, pulse pressure, systolic (SBP) and diastolic blood pressure (DBP) and coronary heart disease (CHD) significantly predicted MA in men and increasing pulse pressure, SBP and DBP were associated with MA in women, adjusted for other cardiovascular risk factors/markers. After excluding individuals with known CHD and untreated hypertension (SBP > or = 140 mmHg, DBP > or = 90 mmHg) and hence a high total risk of cardiovascular disease (CVD), only increasing age was associated with ACR in men and increasing SBP and pulse pressure in women. Smoking, elevated lipid and glucose levels were strongly associated with MA in individuals with a high total risk of CVD than in individuals with a low total risk. CONCLUSION: MA was associated with increasing blood pressure in both genders, age and CHD in men. Other cardiovascular risk factors/markers might be more influential in predicting ACR variation in nondiabetic/nonhypertensive individuals with a high total risk of CVD than in individuals with a low total risk.

Blood pressure and risk of headache: a prospective study of 22 685 adults in Norway.

OBJECTIVES: Prevalence studies of the association between blood pressure and headache have shown conflicting results. The aim was to analyse the relation between blood pressure and risk of headache in a prospective study. METHODS: A total of 22 685 adults not likely to have headache, had their baseline blood pressure measured in 1984-6, and responded to a headache questionnaire at follow up 11 years later (1995-7). The relative risk of headache (migraine or non-migrainous headache) was estimated in relation to blood pressure at baseline. RESULTS: Those with a systolic blood pressure of 150 mm Hg or higher had 30% lower risk (risk ratio (RR)=0.7, 95% CI 0.6-0.8) of having non-migrainous headache at follow up compared with those with systolic pressure lower than 140 mm Hg. For diastolic blood pressure, the risk of non-migrainous headache decreased with increasing values, and these findings were similar for both sexes, and were not influenced by use of antihypertensive medication. For migraine, there was no clear association with blood pressure. CONCLUSION: In the first prospective study of blood pressure and the risk of headache, high systolic and diastolic pressures were associated with reduced risk of non-migrainous headache. One possible explanation may be the phenomenon of hypertension associated hypalgesia, which probably involves the baroreflex system influencing nociception in the brain stem or spinal cord.