Sofia Carlsson

Birth weight and risk of type 2 diabetes: A systematic review

CONTEXT Low birth weight is implicated as a risk factor for type 2 diabetes. However, the strength, consistency, independence, and shape of the association have not been systematically examined. OBJECTIVE To conduct a quantitative systematic review examining published evidence on the association of birth weight and type 2 diabetes in adults. DATA SOURCES AND STUDY SELECTION Relevant studies published by June 2008 were identified through literature searches using EMBASE (from 1980), MEDLINE (from 1950), and Web of Science (from 1980), with a combination of text words and Medical Subject Headings. Studies with either quantitative or qualitative estimates of the association between birth weight and type 2 diabetes were included. DATA EXTRACTION Estimates of association (odds ratio [OR] per kilogram of increase in birth weight) were obtained from authors or from published reports in models that allowed the effects of adjustment (for body mass index and socioeconomic status) and the effects of exclusion (for macrosomia and maternal diabetes) to be examined. Estimates were pooled using random-effects models, allowing for the possibility that true associations differed between populations. DATA SYNTHESIS Of 327 reports identified, 31 were found to be relevant. Data were obtained from 30 of these reports (31 populations; 6090 diabetes cases; 152 084 individuals). Inverse birth weight-type 2 diabetes associations were observed in 23 populations (9 of which were statistically significant) and positive associations were found in 8 (2 of which were statistically significant). Appreciable heterogeneity between populations (I(2) = 66%; 95% confidence interval [CI], 51%-77%) was largely explained by positive associations in 2 native North American populations with high prevalences of maternal diabetes and in 1 other population of young adults. In the remaining 28 populations, the pooled OR of type 2 diabetes, adjusted for age and sex, was 0.75 (95% CI, 0.70-0.81) per kilogram. The shape of the birth weight-type 2 diabetes association was strongly graded, particularly at birth weights of 3 kg or less. Adjustment for current body mass index slightly strengthened the association (OR, 0.76 [95% CI, 0.70-0.82] before adjustment and 0.70 [95% CI, 0.65-0.76] after adjustment). Adjustment for socioeconomic status did not materially affect the association (OR, 0.77 [95% CI, 0.70-0.84] before adjustment and 0.78 [95% CI, 0.72-0.84] after adjustment). There was no strong evidence of publication or small study bias. CONCLUSION In most populations studied, birth weight was inversely related to type 2 diabetes risk.

Coffee consumption, type 2 diabetes and impaired glucose tolerance in Swedish men and women.

Objectives.  The association between coffee consumption, type 2 diabetes and impaired glucose tolerance was examined. In addition, indicators of insulin sensitivity and β‐cell function according to homeostasis model assessment were studied in relation to coffee consumption.

Family history of diabetes in middle-aged Swedish men is a gender unrelated factor which associates with insulinopenia in newly diagnosed diabetic subjects

Summary We have investigated the association of a family history of diabetes with glucose tolerance in a population of Swedish men. All men 35–54 years of age in 1992 and living in four different local municipalities of the outer Stockholm area were screened by questionnaire. From 10 236 completed questionnaires 1622 men, selected for presence of such a history but without known diabetes, as well as 1507 men without a family history underwent an oral glucose tolerance test. Diabetes (2 h-plasma glucose levels > 11.0 mmol/l) was detected in 55 and impaired glucose tolerance (plasma glucose levels 7.8–11.0 mmol/l) in 172 subjects. The odds ratio of diabetes, associated with a family history, was 4.1, confidence interval 2.1–8.3 and for impaired glucose tolerance 1.6, confidence interval 1.2–2.3. Influence of a family history was measurable also within the range of normal 2-h glucose concentrations: compared to 2-h glucose levels < 3.8 mmol/l; the odds ratio associated with a family history was 1.4, confidence interval 1.1–1.7 and 1.3, confidence interval 1.1–1.6 for concentrations 4.8–5.7 mmol/l and 5.8–7.7 mmol/l respectively. The odds ratio of diabetes and impaired glucose tolerance among men with a family history increased with number and closeness of relatives with diabetes but was not affected by the gender of the family member. Overweight (BMI > 25.0 kg/m2) increased the odds ratio of diabetes in subjects with a family history, the odds ratio being 24, confidence interval 3–177, when both conditions were present. In subjects with Type II (non-insulin-dependent) diabetes mellitus discovered during the investigation, the presence of a family history of diabetes was associated with decreased insulin secretion rather than insulin resistance as assessed by fasting insulin, homeostasis model assessment, and the 2-h insulin response to the oral glucose tolerance test. We conclude that a family history of diabetes strongly but independently of gender associates with decreased glucose tolerance. Furthermore, the results are compatible with a major role for low insulin secretion in the diabetogenic influence of a family history of diabetes in middle-aged Swedish men. Lastly, the very high risk for diabetes in middle-aged men with both a family history of diabetes and obesity indicates that such people should, for the purpose of therapeutic intervention, be identified in the general population. [Diabetologia (1999) 42: 15–23]

Influence of Family History of Diabetes on Incidence and Prevalence of Latent Autoimmune Diabetes of the Adult : Results from the Nord-Trondelag Health Study

OBJECTIVE—The aim of this study was to investigate the association between family history of diabetes (FHD) and prevalence and incidence of latent autoimmune diabetes of the adult (LADA), type 1 diabetes, and type 2 diabetes. RESEARCH DESIGN AND METHODS—The results were based on cross-sectional data from 64,498 men and women (aged ≥20 years) who were in the Nord-Trøndelag Health Study, which included 128 cases of LADA, 1,134 cases of type 2 diabetes, and 123 cases of type 1 diabetes. In addition, prospective data on 46,210 subjects, which included 80 incident cases of LADA, observed between 1984 and 1986 and 1995 and 1997 were available. Patients with LADA had antibodies against GAD and were insulin independent at diagnosis. RESULTS—FHD was associated with a four times (odds ratio [OR] 3.92 [95% CI 2.76–5.58]) increased prevalence of LADA. Corresponding estimates for type 2 and type 1 diabetes were 4.2 (3.72–4.75) and 2.78 (1.89–4.10), respectively. Patients with LADA who had FHD had lower levels of C-peptide (541 vs. 715 pmol/l) and were more often treated with insulin (47 vs. 31%) than patients without FHD. Prospective data indicated that subjects with siblings who had diabetes had a 2.5 (1.39–4.51) times increased risk of developing LADA during the 11-year follow-up compared with those without. CONCLUSIONS—This study indicates that FHD is a strong risk factor for LADA and that the influence of family history may be mediated through a heritable reduction of insulin secretion.

Smoking is associated with an increased risk of type 2 diabetes but a decreased risk of autoimmune diabetes in adults: an 11-year follow-up of incidence of diabetes in the Nord-Trøndelag study

Aims/hypothesisWe compared the association between smoking habits and later occurrence of type 2 diabetes on the one hand and between smoking and diabetes with autoimmunity on the other hand.MethodsWe used data from a prospective study of 11-year cumulative incidence of diabetes in the Nord-Trøndelag Health Survey.ResultsConfirming previous reports, heavy smoking (≥20 cigarettes per day) carried an increased relative risk (RR) of type 2 diabetes (n=738, RR=1.64, 95% CI: 1.12–2.39). In contrast, smoking reduced the risk of latent autoimmune diabetes in adults (LADA) and of traditional type 1 diabetes (LADA n= 81, RR=0.25, 95% CI: 0.11–0.60; type 1 diabetes, n=18, RR=0.17, 95% CI: 0.04–0.73).Conclusions/interpretationsThe results indicate that nicotine influences autoimmune processes in human diabetes.

Alcohol consumption is associated with reduced risk of Type 2 diabetes and autoimmune diabetes in adults: results from the Nord‐Trøndelag health study

Diabet. Med. 30, 56–64 (2013)

Low physical activity and mortality in women: Baseline lifestyle and health as alternative explanations

Aims: The aim of this study was to investigate the association between physical activity and mortality in post-menopausal women. In addition, the authors wanted to investigate to what extent this association could be attributed to confounding from other lifestyle factors, and to reverse causation due to a number of common health problems that may inhibit the ability to exercise. Methods: A total of 27,734 women aged 51—83 years from the Swedish Mammography Cohort were investigated. In 1997 they responded to a detailed questionnaire including questions on physical activity, diet, alcohol intake, smoking, and medical problems. During follow-up in 1999—2004, 1,232 deaths were identified by linkage to the National Population Register. Results: Women with low physical activity (≤35 MET*h/day) had a 3.22 times increased mortality (95% confidence interval (CI)=2.35—4.43) compared with the most active women (>50 MET*h/day). No increased risk was seen in women with moderate compared with high physical activity. Sedentary women tended to have a less healthy lifestyle and more health problems at baseline, e.g. almost 30% of them reported high blood pressure compared with less than 20% of active women. Baseline medical problems and lifestyle factors such as smoking, diet, and education accounted for 30% of the excess risk seen in sedentary women (24% and 6% respectively). Conclusions: This study indicates that even fairly small amounts of activity will reduce mortality in older women. However, sedentary women seemed to be a selected group with more medical problems and a less healthy lifestyle. The findings indicate that the association between physical inactivity and mortality will be overestimated if this is not taken into account.

Smoking Is Associated With Reduced Risk of Autoimmune Diabetes in Adults Contrasting With Increased Risk in Overweight Men With Type 2 Diabetes: A 22-year follow-up of the HUNT study

OBJECTIVE To investigate the association between smoking habits and risk of autoimmune diabetes in adults and of type 2 diabetes. RESEARCH DESIGN AND METHODS We used data from the three surveys of the Nord-Trøndelag Health Study, spanning 1984–2008 and including a cohort of 90,819 Norwegian men (48%) and women (52%) aged ≥20 years. Incident cases of diabetes were identified by questionnaire and classified as type 2 diabetes (n = 1,860) and autoimmune diabetes (n = 140) based on antibodies to glutamic decarboxylase (GADA) and age at onset of diabetes. Hazard ratios (HRs) adjusted for confounders were estimated by Cox proportional hazards regression models. RESULTS The risk of autoimmune diabetes was reduced by 48% (HR 0.52 [95% CI 0.30–0.89]) in current smokers and 58% in heavy smokers (0.42 [0.18–0.98]). The reduced risk was positively associated with number of pack-years. Heavy smoking was associated with lower levels of GADA (P = 0.001) and higher levels of C-peptide (964 vs. 886 pmol/L; P = 0.03). In contrast, smoking was associated with an increased risk of type 2 diabetes, restricted to overweight men (1.33 [1.10–1.61]). Attributable proportion due to an interaction between overweight and heavy smoking was estimated to 0.40 (95% CI 0.23–0.57). CONCLUSIONS In this epidemiological study, smoking is associated with a reduced risk of autoimmune diabetes, possibly linked to an inhibitory effect on the autoimmune process. An increased risk of type 2 diabetes was restricted to overweight men.

Shared genetic influence of BMI, physical activity and type 2 diabetes: a twin study

Aims/hypothesisThe aim of this study was to examine the long-term associations of BMI and physical activity with type 2 diabetes, and to estimate shared genetic components of these traits.MethodsWe used data from the Swedish Twin Registry on 23,539 twins born 1886–1958 who answered questionnaires between 1967 and 1972 and were followed up until 1998. The risk of type 2 diabetes in relation to BMI and physical activity was assessed by Cox regression. Structural equation models were used to estimate genetic and environmental variance components and genetic correlations.ResultsThe risk of type 2 diabetes increased with BMI (HR 1.32 [95% CI 1.29, 1.35] per kg/m2) and decreased with physical activity (HR 0.56 [95% CI 0.39, 0.80] for high vs low). Heritability was estimated to be 77% (95% CI 54%, 83%) for type 2 diabetes, 65% (95% CI 58%, 73%) for BMI, and 57% (95% CI 47%, 67%) for physical activity. The genetic correlation with type 2 diabetes was 0.43 (95% CI 0.31, 0.58) for BMI and −0.23 (95% CI −0.46, 0.02) for physical activity, implying that 18% (95% CI 9%, 34%) of the genetic influence on type 2 diabetes is shared with BMI and 5% (95% CI 0%, 20%) with physical activity.Conclusions/interpretationIndications of shared genetic effects are found for BMI and type 2 diabetes, which suggests that these traits are partly influenced by the same genetic factors. In contrast, our findings suggest that the genes related to physical activity are essentially different from those associated with type 2 diabetes.

The incidence of SUDEP A nationwide population-based cohort study

Objective: To identify all cases of sudden unexpected death in epilepsy (SUDEP) among people in Sweden during 1 year and to determine the SUDEP incidence in relation to age, sex, and psychiatric comorbidity. Methods: We included all individuals with a hospital-based ambulatory care or hospital discharge diagnosis of epilepsy in the Swedish National Patient Registry during 1998–2005 who were alive on January 1, 2008. Deaths during 2008 were identified by linkage to the National Cause of Death Registry. Death certificates, medical charts, and police and autopsy reports were extensively reviewed to identify SUDEP cases. Results: Of 57,775 epilepsy patients alive on January 1, 2008, 1,890 died (3.3%) during 2008. Of these, 99 met the Annegers SUDEP criteria (49 definite, 19 probable, and 31 possible). SUDEP accounted for 5.2% of all deaths and 36% of deaths in the 0–15 years age group. The incidence of definite/probable SUDEP was 1.20/1,000 person-years, and higher in men (1.41) than in women (0.96). All SUDEP cases <16 years were in boys. SUDEP incidence at ages <16, 16–50, and >50 years was 1.11, 1.13, and 1.29, respectively, per 1,000 person-years. The incidence was 5-fold increased among female patients with psychiatric comorbidities compared to those without. Epilepsy was mentioned on the death certificate in only 62 of the 99 (63%) SUDEP cases. Conclusions: Methods relying on death certificates underestimate SUDEP incidence. SUDEP risk has been underestimated especially in boys and in older people regardless of sex. Patients with psychiatric comorbidities, women in particular, are at increased SUDEP risk.