TABLE 1.

Characteristics of studies included for quantitative analysis

First author and year	Type of study	Setting	Country	Study period	Number of participants	Definition of T1DM	Fracture ascertainment	Age (y)	Total fracture events (fractured/total)	Fracture type	Fracture events by gender in those aged between 18–50 years (fractured/total)		OR/RR/HR	Variables adjusted
Zhukouskaya et al., 201320	Cross-sectional	Hospital outpatient	Belarus	2007–2011	82 T1DM (26M:56F); 82 controls (22M:60F)	American Diabetes Association criteria	Vertebral fracture assessment and spinal radiographs	20–55	20/82 of T1DM vs 5/82 of controls	Vertebral	Males: 6/26 T1DM; 1/22 controls	Females: 14/56 T1DM; 4/60 controls	OR 4.20, 95% Cl 1.40–12.70, P < .01	Age, sex, BMI, lumbar spine BMD
Weber et al., 201514	Prospective cohort	Population	UK	1994–2002	Total 30 394 T1DM (17 074M:13 347F); 303 872 controls (170 421M:133 451F)	Medical diagnoses (read codes) specific to T1DM or diabetes and <35 years old	Diagnosis codes from outpatient electronic medical records consistent with incident fracture, classified by site; surgically-induced fractures or those associated with birth trauma or metastases were excluded	0–89	2615/30 394 of T1DM vs 18 624/30 3872 of controls	Any fracture	Males: 779/10 874 T1DM; 5367/109 016 controlsa	Females: 431/8193 T1DM; 2440/82 156 controlsa	Males: HR 1.55, 95% Cl 1.44–1.67, P < .001a; Females: 1.76 95% Cl 1.58–1.96, P < .001a	Steroid use, prior fracture, CKD
										Hip	Males: 21/10 983 T1DM; 75/109 927 controlsa	Females: 14/8321 T1DM; 28/82 390 controlsa	Males: HR 2.55, 95% Cl 1.52–4.26, P < .001a; Females: HR 3.36, 95% Cl 1.61–7.10, P = .001a
Hothersall et al., 201416	Retrospective cohort study	Population/registry-based	Scotland	2005–2007	21 033 T1DM/59 585 person-years; controls 3.66million/10 980 599 person-years	Clinical and prescription history (no evidence of lengthy diabetes duration prior to insulin prescription, no co-prescription of oral anti-diabetic drugs except for metformin)	Incident hip fracture admissions in 2005 to 2007 by linkage of diabetes register to national hospital admissions data (ICD codes)	20–84	105/21 033 of T1DM vs 11 733/36 60000 of controls	Hip	Males: 14/8844 of T1DM; 331/1026 350 of controlsb	Females: 7/6649 of T1DM; 160/107 6510 of controlsb	Males: RR 5.4, 95% CI 3.5–8.3, P < .001b; Females: RR 7.9, 95% Cl 3.4–18.5, P < .001b	Age, sex and calendar year
Vestergaard et al., 200919	Case-control	Population	Denmark	2000	4369 T1DM, 484 615 controls	WHO standards	National Hospital Discharge Register & ICD codes	43 ± 27	1703/4369 of T1DM vs 122 952/371 296 of controls	Any fracture	Males: 284/797 of T1DM; 26 201/105 458 of controlsc	Females: 139/344 of T1DM; 13 677/55 132 of controlsc	Males: OR 1.67, 95% Cl 1.45–1.94, P < .001c; Females: OR 2.06, 95% Cl 1.66–2.55, P < .001c	Macro- and micro-vascular complications
Danielson et al., 200921	Matched, nested cross-sectional	Population	USA	2005	T1DM females 75; controls 75	New cases of T1DM defined as diagnosis ≤age 30, clinical symptoms of hyperglycaemia and insulin-requiring	Self-reported fractures confirmed by physician or radiograph	18–50	Fracture: 28 T1DM, 18 controls	Any	N/A	Females: 28/75 of T1DM; 18/75 of controls	Females: OR 2.3, 95% Cl 1.0–5.2, P < .05	Not reported
Strotmeyer et al., 200622	Cross-sectional	Population (volunteer subgroup from prospective study)	USA	Un-known	T1DM females 67; controls 237	Premenopausal women on diabetes registry diagnosed at age <17 years in hospital	Self-reported	35–55	Fracture: T1DM 33.3% vs controls 22.6%, age-adjusted OR 1.89 (95% Cl 1.02–3.49)	Any fracture after age 20 (site not specified)	N/A	Females: 22/67 of T1DM; 54/237 of controls	Females: OR 1.89, 95% Cl 1.02–3.49, P > .05	Age

BMD, bone mineral density; T1DM, type 1 diabetes mellitus.

^aPart of a secondary analysis of dataset initially assembled to describe fracture incidence from birth to 89 years, using data from The Health Improvement Network; data obtained from investigators through personal communication.

^bPart of a secondary analysis of original data set; data obtained from investigators through personal communication.

^cPart of a secondary analysis of original data set; data obtained from investigators through personal communication.