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M McGue

Publications and source records attributed to M McGue.

At least 19 recordsLinked to original sources
PubMed2005

Long-term effects of migraine on cognitive function: a population-based study of Danish twins.

OBJECTIVE: To investigate the cognitive functioning of migraineurs vs nonmigraineurs in a large population-based sample of middle-aged twins where headache diagnoses were established by neurologists. METHODS: Twins identified through the population-based Danish Twin Registry participated in face-to-face structured interviews, which included cognitive tests and two previously validated questions screening for migraine. Twins who screened positive for migraine and their co-twins were invited to participate in a telephone-based interview conducted by neurologists, who established headache diagnoses according to the International Headache Society criteria. Cognitive scores on fluency, digit span, delayed word recall, and symbol digit substitution test were compared between migraineurs and nonmigraineurs. Comparisons within monozygotic and dizygotic same sex twin pairs discordant for migraine were also performed. RESULTS: Of the 1,789 twins who were eligible for inclusion in the present study, 1,393 (77.8%) were interviewed. A diagnosis of migraine was established in 536 twins (migraine without aura n = 347; migraine with aura n = 157). Average scores on cognitive tests in twins with migraine or one of the migraine subtypes did not differ from those of nonmigraineurs in any of the tests. Comparisons within twin pairs discordant for migraine produced highly comparable results. Adjustment for possible confounders and stratification by cumulated number of lifetime attacks did not influence the results. CONCLUSIONS: A lifetime diagnosis of migraine was not associated with cognitive deficits in middle-aged subjects.

Aged↗
PubMed2002

Frequency and heritability of depression symptomatology in the second half of life: evidence from Danish twins over 45.

BACKGROUND: Self-reported depressive symptoms among the elderly have generated considerable interest because they are readily available measures of overall well-being in a population often thought to be at special risk for mental disorder. METHOD: The heritability of depression symptoms was investigated in a sample of 2169 pairs of Danish twins (1033 MZ and 1136 same sex DZ) ranging in age from 45 to over 95. Twins completed an interview assessment that identified symptoms of depression, which were scored on Affective, Somatic and Total scales. RESULTS: Overall heritability estimates (a2) for the Affective (a2 = 0.27, (95% CI 0.22-0.32)). Somatic (a2 = 0.26, (0.21-0.32)), and Total (a2 = 0.29, (0.22-0.34)) scales were all moderate, statistically significant and similar to results from other studies. To assess possible variations in heritability across the wide age span, the sample was stratified into age groups in increments of 10 years. The magnitude of heritable influence did not vary significantly with age or sex. Somatic scale heritability tended to be greater for females than for males, though this difference was not statistically significant. The genetic correlation between the Affective and Somatic scales was 0.71, suggesting substantial common genetic origins. CONCLUSIONS: Though the frequency of self-reported depressive symptoms increased with age in this sample, their heritability did not.

Aged↗
PubMed2001

Cholecystokinin (CCK) gene as a possible risk factor for smoking: a replication in two independent samples.

BACKGROUND: CCK is a satiety neuropeptide. Animal studies have shown that both acute and chronic exposure to nicotine results in weight loss which is associated with an increase in hypothalamic CCK and that CCK antagonists ameliorate symptoms of nicotine withdrawal. A major detriment to smoking cessation, especially in women, is the fear of gaining weight. These observations suggested that genetic variants in the CCK gene might be a possible risk factor for smoking. METHODS: To test this hypothesis we examined the association of the C-45T promoter polymorphism in the Sp1 binding region of the CCK gene with smoking and BMI in two independent groups of subjects. RESULTS: Group 1 consisted of 191 Caucasian women participating in an obesity study. The T allele was present in 15% of women who had never smoked, 20% of ex-smokers, and 58% of current smokers, P < or = 0.0014. The T allele was present in 26.8% of ever-smokers (ex-smokers + current smokers). There was no association with BMI. Group 2 consisted of 725 parents of twins from the Minnesota Twin and Family Study of substance abuse. Logistic regression analysis showed that a diagnosis of nicotine dependence was significantly associated with the T allele (P < or = 0.002) and with gender (males > females) (P < or = 0.001), but not with BMI (P < or = 0.68). The T allele was present in 15.9% of parents who had never smoked and 24.7% of ever-smokers, very similar to the results for group 1. INTERPRETATION: These results are consistent with a role of the CCK gene as a risk factor for smoking.

Adult↗
PubMed2001

Genetic and environmental influences on anorexia nervosa syndromes in a population-based twin sample.

BACKGROUND: Genetic and environmental influences on broadly-defined anorexia nervosa (AN) syndrome were examined in a population-based twin sample. METHODS: AN syndrome was assessed in 672 female 17 year-old twins using structured interviews and a self-report questionnaire. RESULTS: Twenty-six probands with AN syndrome were identified. Biometrical model-fitting analyses indicated that genetic and non-shared environmental factors accounted for 74% and 26% of the variance in AN syndrome, respectively. CONCLUSIONS: Findings support previous research indicating significant genetic and non-shared environmental influences on AN syndromes.

Adolescent↗
PubMed2001

The heritability of cognitive functioning in very old adults: evidence from Danish twins aged 75 years and older.

Heritable influences on cognitive functioning were investigated in a sample of 403 pairs of like-sex Danish twins aged 75 years and older. Twins completed the Mini-Mental State Examination and 3 other cognitive tests. Genetic factors accounted for 26-54% of the variance on these measures, with the balance being due to environmental factors that create differences rather than similarities among reared-together relatives. Deleting twins with severe cognitive impairment had little effect on the results, indicating that the heritability of cognitive functioning was not due entirely to genes affecting dementia. Neither age nor gender moderated twin similarity, and differential social contact could not account for correlation differences between monozygotic and dizygotic twins. These results replicate G. E. McClearn et al.'s (1997) study in indicating substantial genetic influences on late-life cognitive functioning.

Age Factors↗
PubMed2001

Perceived victimization moderates self-reports of workplace aggression and conflict.

A sample of 489 employed men between 32 and 36 years old responded to questions concerning rates of having engaged in workplace aggression and conflict. These individuals also completed a personality inventory and questionnaires related to past antisocial behavior and alcohol abuse. Consistent with prior research, workplace aggression and conflict were significantly correlated with particular personality variables (stress reaction, aggression, and control) as well as with general past antisocial behavior and alcohol abuse. Furthermore, these relationships were moderated by the perception of being victimized by others (alienation), with such perceptions strengthening associations between workplace aggression and other risk factors. These interaction effects, which cannot plausibly be attributed to the use of a self-report criterion, could have important implications for understanding and predicting aggression and conflict behavior within organizations.

Aggression↗
PubMed2001

Functional status and self-rated health in 2,262 nonagenarians: the Danish 1905 Cohort Survey.

OBJECTIVES: To describe the functional capacity and self-rated health of a large cohort of nonagenarians. DESIGN: A cross-sectional survey of all Danes born in 1905 (92-93 years of age), carried out August to October 1998. SETTING: Participants' homes. PARTICIPANTS: Two thousand two hundred and sixty-two nonagenarians, corresponding to a participation rate of 63% (of these, 20% participated by proxy). MEASUREMENTS: Activities of daily living (ADLs) and self-rated health were assessed by interview. Five items from Katz's ADLs (bathing, dressing, transfer, toileting, and eating) were used to construct a three-level five-item ADL scale (not disabled (no disabilities), moderately disabled (1-2 disabilities), severely disabled (3-5 disabilities)). From responses to a more extensive list of questions on ADLs (26 items), we identified scales of strength and agility by means of factor analysis. Furthermore, a 26-item ADL scale was made. Physical performance tests (chair stand, timed walk, lifting a 2.7 kg box, maximum grip-strength, and flexibility tests) were performed among nonproxy responders. RESULTS: According to the five-item ADL scale, 50% of the men and 41% of the women were categorized as not disabled, while 19% and 22%, respectively, were categorized as severely disabled. The five-item ADL scale correlated highly with the 26-item ADL scale (r = 0.83). The ADL scales showed moderate-to-good correlation with each other (r = 0.74-0.83), and with the physical performance tests (r = 0.31-0.58). Only 3.7% of the women and 6.3% of the men walked (normal pace) with a speed of at least 1 meter per second, which is the minimum walking speed required to cross signaled intersections in Denmark. A total of 56% considered their health to be excellent or good. Of the participants, 74% were always or almost always satisfied with their lives, even though only 45% reported that they "felt well enough to do what they wanted." The analyses showed that no single ADL item seemed to be of particular importance for how the participants rated their health. CONCLUSION: The Danish 1905 cohort survey is the largest and the only nationwide survey of a whole birth-cohort of nonagenarians. A total of 2,262 fairly nonselected nonagenarians participated. The level of both self-reported disability and functional limitations measured by physical performance tests among nonagenarians was high. Despite their lower mortality, women were more disabled than men and did not perform as well as men in the physical performance tests. Nevertheless, the majority of the participants considered their health to be good and were satisfied with their lives.

Activities of Daily Living↗
PubMed2001

Altruism and antisocial behavior: independent tendencies, unique personality correlates, distinct etiologies.

The relationship between altruism and antisocial behavior has received limited attention because altruism and antisocial behavior tend to be studied and discussed in distinct literatures. Our research bridges these literatures by focusing on three fundamental questions. First, are altruism and antisocial behavior opposite ends of a single dimension, or can they coexist in the same individual? Second, do altruism and antisocial behavior have the same or distinct etiologies? Third, do they stem from the same or from distinct aspects of a person's personality? Our findings indicate that altruism and antisocial behavior are uncorrelated tendencies stemming from different sources. Whereas altruism was linked primarily to shared (i.e., familial) environments, unique (i.e., nonfamilial) environments, and personality traits reflecting positive emotionality, antisocial behavior was linked primarily to genes, unique environments, and personality traits reflecting negative emotionality and a lack of constraint.

Adult↗
PubMed2001

Do genetic factors contribute to the association between birth weight and blood pressure?

OBJECTIVES: To evaluate whether genetic factors contribute to the association between low birth weight and increased blood pressure among adolescents. DESIGN: Historical cohort study of twin pairs. It was evaluated whether (1) a negative association between birth weight and systolic blood pressure was found in the overall twin sample and (2) whether the intrapair difference in birth weight correlated with the intrapair difference in systolic blood pressure-thereby controlling for the effect of genetic factors (all in monozygotic and on average half in dizygotic pairs). SETTING: The Minnesota Twin Family Study. PARTICIPANTS: 1311 pairs of adolescent twins. MAIN RESULTS: A negative association between birth weight and systolic blood pressure was retrieved in the overall sample. The regression coefficient after controlling for current weight was -1.88 mm Hg/kg (SE 0.61), which corresponds to results from previous studies of singleton adolescents. The regression coefficient fell to -0.64 mm Hg/kg (SE 0.86) when the intrapair analyses were used. The largest reduction was observed among monozygotic twins: from -2.44 mm Hg/kg (SE 0.75) in the overall monozygotic twin sample to -1.06 mm Hg/kg (SE 1.14) in the analyses of the within monozygotic pair differences. CONCLUSION: The association between low birth weight and increased blood pressure later in life is well established. "The fetal programming hypothesis" suggests that the association is caused by intrauterine malnutrition while a new hypothesis "the fetal insulin hypothesis" proposes that genetically determined insulin resistance also contributes significantly to the association. A recent twin study of middle aged twins showed no evidence for an influence of genetic factors while this larger study provides support for the fetal insulin hypothesis: the association between birth weight and blood pressure attenuated among adolescents when genetic factors were controlled. Together this suggests an important contribution of genetic factors to the association between fetal growth and systolic blood pressure in adolescence.

Adolescent↗
PubMed2001

The Danish 1905 cohort: a genetic-epidemiological nationwide survey.

OBJECTIVES: The authors studied nonagenarians, a rapidly growing age group whose cognitive and physical abilities have yet to be investigated systematically. METHODS: All Danes born in 1905 were invited to participate in a home-based 2-hour multidimensional interview, including cognitive and physical performance tests and collection of DNA, carried out by lay interviewers. Population-based registers were used to evaluate representativeness. RESULTS: There were 2,262 participants. A total of 1,632 (72%) gave a DNA sample. Participants and nonparticipants were highly comparable with regard to marital status, institutionalization, and hospitalization patterns, but men and rural area residents were more likely to participate. Six months after the survey began, 7.2% of the participants and 11.8% of the nonparticipants had died. DISCUSSION: Despite the known difficulties of conducting surveys among the extremely old, it was possible to conduct a nationwide survey, including collection of DNA, among more than 2,000 fairly nonselected nonagenarians using lay interviewers.

Aged↗
PubMed2001

Event-related potentials and comorbidity in alcohol-dependent adult males.

The present study examined event-related potentials (ERPs) elicited by a visual discrimination task in a community sample of adult males with a lifetime diagnosis of alcohol dependence. Study participants were subtyped by the presence of additional comorbid disorders (antisocial personality, depression, and drug abuse or dependence). In all groups of alcohol-dependent subjects, even those without any additional comorbid disorders, P3 amplitude differed from that of a comparison group. Alcohol-dependent subjects with a diagnosis of illicit drug abuse or dependence, especially if they had antisocial personality as well, had the smallest amplitude responses. The amplitude profile of the P3 across the parietal electrodes used as active sites was flattened among alcoholic subjects, with P3 amplitude disproportionately reduced at the midline. Among alcoholic subjects with a lifetime diagnosis of depression, the flattened amplitude profile was due to elevated mean amplitude of the P3 at lateral leads, especially P4, relative to the comparison group. Alterations in ERP responses appear to be a general characteristic of alcoholism in men, although the presence of other comorbid disorders, particularly drug abuse or dependence together with antisocial personality, results in the greatest reductions in P3 amplitude.

Adult↗
PubMed2001

Origins and consequences of age at first drink. I. Associations with substance-use disorders, disinhibitory behavior and psychopathology, and P3 amplitude.

BACKGROUND: Although an early age at first drink has been repeatedly associated with substantially elevated rates of alcoholism, the mechanisms underlying this association remain unclear. We investigated whether the association of age at first drink (AFD) with alcoholism was more consistent with the hypothesis that the former causes the latter or the hypothesis that both are manifestations of some common vulnerability. METHODS: We investigated whether substance use and mental health disorders, education, IQ, and personality were associated with AFD in a sample of 2670 adults; whether P3 amplitude was associated with AFD in a sample of 1127 17 year olds; and whether indicators of disinhibitory psychopathology assessed at age 11 predicted AFD by age 14 in a sample of 1343 adolescents. RESULTS: In adults, AFD was associated not only with alcohol dependence, but also with a broad array of indicators of disinhibitory behavior and psychopathology including nicotine dependence, illicit drug abuse and dependence, conduct disorder, antisocial personality disorder, underachievement in school, and the personality trait of constraint. In 17 year olds, AFD was also associated with reduced P3 amplitude, a well-documented psychophysiological marker of alcoholism risk. Finally, in the early-adolescence sample, measures of behavioral disinhibition, including oppositionality, hyperactivity/impulsivity, and inattentiveness assessed at age 11 predicted drinking onset by age 14. CONCLUSIONS: Our findings indicated that AFD is not specifically associated with alcoholism but rather is correlated with a broad range of indicators of disinhibited behavior and psychopathology. Moreover, individuals who first drink at a relatively early age manifest elevated rates of disinhibitory behavior and psychopathology before they first try alcohol. Taken together, these findings suggest that the association of AFD with alcoholism reflects, at least in part, a common underlying vulnerability to disinhibitory behavior. Whether an early AFD directly influences risk of adult alcoholism remains unclear.

Adolescent↗
PubMed2001

Origins and consequences of age at first drink. II. Familial risk and heritability.

BACKGROUND: The association of age at first drink (AFD) and alcoholism may reflect a common inherited vulnerability to disinhibitory behavior and psychopathology rather than a direct influence of the former on the latter. We tested the common-inherited-vulnerability hypothesis by determining whether AFD is familial and heritable. METHODS: A sample of 1,232 14-year-old twins was classified according to their biological parents' AFD. RESULTS: Lifetime symptoms of externalizing disorders (i.e., conduct disorder and oppositional defiant disorder) were significantly higher in the sons but not the daughters of parents whose AFD came before age 15 years. Offspring symptoms of internalizing disorders (i.e., major depressive disorder, separation anxiety disorder, and overanxious disorder) were not significantly associated with parental early use of alcohol in either sons or daughters. Early use of alcohol in mothers but not fathers was associated with a significant increase in both sons' and daughters' risk of alcohol use by age 14. The contribution of genetic and environmental factors to risk of early alcohol use was investigated in a sample of 416 monozygotic (MZ) and 225 like-sex dizygotic (DZ) 14-year-old twin pairs. Twin similarity for early alcohol use was substantially greater in MZ than DZ twins in boys but about equally similar in MZ and DZ twins in girls. Estimated heritability of early alcohol use was significantly greater in boys (55%) than girls (11%), in part because the genetic factors underlying symptoms of disinhibitory psychopathology contributed more to risk of early alcohol use in boys than girls. CONCLUSIONS: Early use of alcohol is familial and, at least in males, heritable. The familial transmission of early alcohol use is caused in part by genetic risk for disinhibitory psychopathology in males and to shared environmental factors in girls. These results provide some support for a common-inherited-vulnerability hypothesis, and suggest that the processes underlying early alcohol use may differ in boys and girls.

Adolescent↗
PubMed2000

Genetic and environmental influences on adolescent substance use and abuse.

The inheritance of substance use and abuse among adolescents was investigated in a sample of 626 male and female 17-year-old twin pairs. Both licit (tobacco) and illicit (e.g., marijuana, amphetamines) substance use and abuse was assessed and analyzed using standard biometric methods. The heritability of use and abuse of illicit substances was modest (25% or less), whereas the heritability of tobacco use and nicotine dependence was substantial (40% to 60%). There was no evidence that gender moderated the strength of genetic influences. Shared environmental influences were substantial for all substance use measures. The finding of greater genetic influence on the use and abuse of a licit substance than on the use and abuse of illicit substances suggests that inherited risk to drug abuse is considerably moderated by environmental control, at least in adolescence. The finding of significant environmental influences on all substance use measures underscores the importance of intervention on early adolescent substance use, a known predictor of adult substance abuse and dependence.

Adolescent↗
PubMed2000

Physical similarity and twin resemblance for eating attitudes and behaviors: a test of the equal environments assumption.

The Equal Environments Assumption (EEA) in twin studies of eating pathology was investigated by examining the hypothesis that twin resemblance for eating attitudes and behaviors is affected by their degree of physical similarity. Eating attitudes and behaviors were assessed in 338 female adolescent twin pairs with a revised version of the Eating Disorder Inventory (EDI). General physical similarity as well as body size/shape similarity were assessed using ratings of color photographs, ratings of body shape, and body mass index. All physical similarity assessments were conducted blind to twin zygosity. Significant associations between physical similarity and twin similarity for eating attitudes and behaviors were not found. Mean EDI within-twin pair absolute difference scores did not differ significantly among more versus less physically-similar groups. Additionally, correlation and regression analyses failed to find a significant association between EDI absolute difference scores and physical similarity indices. The current findings provide support for the EEA in twin studies of eating attitudes and behaviors.

Adolescent↗
PubMed2000

Evidence for a genetic etiology of early-onset delinquency.

Age at onset of antisocial behavior discriminates persistent and transitory offenders. The authors proposed that early-onset delinquency has an underlying genetic influence that manifests in problems related to inhibition, whereas late-onset delinquency is more environmentally mediated. To test these notions, they selected 36 early starters, 86 late starters, and 25 nondelinquent controls from a large sample of 11-year-old twins and compared them on several measures related to inhibition and a peer group measure. As expected, early starters had more psychological, behavioral, and emotional problems related to inhibition than late starters and controls. A longitudinal analysis indicated an increase an antisocial behavior among peers of late starters shortly before their delinquency onset. Family history data and a twin analysis provided evidence of greater genetic influence on early-onset than late-onset delinquency.

Adolescent↗
PubMed2000

Genetic and environmental influences on functional abilities in Danish twins aged 75 years and older.

BACKGROUND: Functional abilities vary widely among elderly persons. The determinants of this variation are probably multiple and include normal aging processes as well as disease expression. This study estimates the relative importance of genetic and environmental factors to variation in functional abilities in elderly persons. METHODS: We conducted a survey among all Danish twins aged 75 years and older who were identified in the population-based Danish Twin Registry. Interviews were conducted with 77% (7% by proxy responders) of the 3099 individuals in the study population. Functional abilities were assessed by validated Danish survey instruments and were scored on three scales. Heritability (proportion of the population variance attributable to genetic variation) was estimated using structural equation analyses. RESULTS: Structural equation analyses revealed a substantial heritability (34%-47%) for the three functional ability scores among the women aged 80 years and older compared with a more modest heritability (15%-34%) among the women aged 75-79 years. The remaining variation could be attributed to individuals' nonfamilial environments. Comparisons of the functional abilities of twins with living versus deceased co-twins also suggested a difference in the genetic influence for the two age groups. Although heritability estimates were uniformly low in the male participant sample, the size of the sample was not sufficiently large to allow for precise estimates of heritability. CONCLUSION: For women we found that the effect of genetic factors on functional abilities increases with age and accounts for one third to one half of the variation among individuals aged 80 years and older. An understanding of the genetic mechanisms underlying functional abilities in the oldest individuals may enhance the possibilities for improving health in the elderly population by modifying environmental factors.

Activities of Daily Living↗